The Large Binocular Telescope uses two 8.4-m diameter primary mirrors
mounted side-by-side. With the arrival of the second near-infrared
spectrometer and the second optical spectrometer, the telescope is
observing with both apertures essentially all the time. Adaptive
optics loops are routinely closed with natural stars on both sides for
combined beam observations. Twin laser guide star constellations have
been installed for GLAO observations.

The existing large single dish radio telescopes of the 100m class (Effelsberg, Green Bank) were built in the 70ties and 90ties. With some active optics they work now down to millimeter wavelength and are limited in their wavelength range mostly by the seeing of their site. There may be science cases where Terahertz capabilities of huge single dish telescopes at higher sites would open new scientific opportunities. The paper gives an overview on the available state-of-the-art technologies for Terahertz dishes up to 160m and will present an outlook on design options, technological frontiers and cost estimates.

We present Project Solaris, a network of four autonomous observatories in the Southern Hemisphere. The Project’s primary goal is to detect and characterize circumbinary planets using the eclipse timing approach. This method requires high-cadence and long time-span photometric coverage of the binaries’ eclipses, hence the observatories are located at sites having similar separation in longitude and nearly identical latitudes: South African Astronomical Observatory, Republic of South Africa (Solaris-1 and -2), Siding Spring Observatory, Australia (Solaris-3) and Complejo Astronómico El Leoncito, Argentina (Solaris-4). The headquarters coordinating and monitoring the network is based in Toruń, Poland. All four sites are operational as of December 2013.
The instrument and hardware configurations are nearly identical, with differences arising from the local infrastructural and technical conditions, mainly in case of Solaris-4. Each site is equipped with a 0.5-m Ritchey–Chrétien or Schmidt-Cassegrain optical tube assembly mounted on a direct-drive modified German equatorial mount along with a set of instruments: field rotator, filter wheel and high grade photometric camera. All components are motorized, including the focuser and mirror covers. Computer, power and networking components are installed in rack cabinets. Everything is housed in sandwiched fiberglass clamshell 3.5-m diameter robotized domes. Due to the exceptional remoteness, the Argentinian site is additionally equipped with a 20-ft office container.
In the paper we discuss the design requirements of robotic observatories aimed to operate autonomously as a global network with concentration on efficiency, robustness and modularity. We describe our systems engineering approach to satisfy these rigorous conditions and the actual implementation along with concrete examples and solutions. We present the design and implementation of low-level security, Heating Ventilation and Air Conditioning (HVAC), data logging and notification systems. We describe the weather monitoring components, including redundant weather stations, lightning detection systems and distributed temperature and humidity sensors. We present the electrical, dedicated grounding and lighting protection system design and robust fiber data transfer interfaces in electrically demanding conditions. We outline custom and tailored solutions developed specifically for the project – both in terms of hardware and software. We discuss the outcomes of our design as well as the resulting software engineering requirements. Custom high-level industry-grade software has been designed and implemented specifically for the use of the network. The software architecture and technological details constitute a vast and separate topic, thus are not part of this paper.
We also present a newly introduced spectroscopic mode of operation commissioned for tests on the Solaris-4 telescope. Using a compact échelle spectrograph (~20 000 resolution) mounted directly on the imaging train of the telescope, we are able to remotely acquire spectra. A custom Guide and Acquisition Module (GAM) allows us to automatically switch between photometric and spectroscopic modes. A fully robotic spectroscopic mode is planned for 2015.

A new telescope project, called PLANETS is coming to the Haleakala High Altitude Observatory in Maui, Hawaii. This telescope is optimized for spectral and spectropolarimetric observations of solar system planets and exoplanets. It consists of an off-axis 1.85m diameter primary mirror with Gregorian and Coude optics on an equatorial mount. The telescope will have smooth (1.5nm microroughness) mirror optical surfaces, and is being polished with a new technology called HyDra. This zero-pressure deterministic polishing method is highly efficient and yields high-quality optical surfaces.

The Hobby-Eberly Telescope (HET) is an innovative large telescope of 9.2 meter aperture, located in West Texas at the McDonald Observatory. The HET operates with a fixed segmented primary and has a tracker, which moves the four-mirror corrector and prime focus instrument package to track the sidereal and non-sidereal motions of objects. A major upgrade of the HET is in progress that will substantially increase the pupil size to 10 meters and the field of view to 22 arcminutes by replacing the corrector, tracker, and prime focus instrument package. In addition to supporting the existing suite of instruments, this wide field upgrade will feed a revolutionary new integral field spectrograph called VIRUS, in support of the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX). The upgrade is being installed and this paper discusses the current status.

The University of Tokyo Atacama Observatory Project is to construct a 6.5m infrared telescope at the summit of Co. Chajnantor (5640m altitude) in northern Chile, promoted by University of Tokyo. Thanks to the dry climate (PWV~0.5mm) and the high altitude, it will achieve excellent infrared performance from the NIR to MIR wavelength. It has entered into a construction phase in 2013. The telescope mount is at a final design phase, an F/1.25 borosillicate light-weighted primary mirror is being polished, and two facility instruments are almost completed. The telescope is now scheduled to see the first light in 2017.

The Cherenkov Telescope Array (CTA), the next generation very high energy gamma-ray observatory, will consist of three types of telescopes: large (LST), medium (MST) and small (SST) size telescopes.
The small size telescopes are dedicated to the observation of gamma-rays with energy between a few TeV and few hundreds of TeV.
The single-mirror small size telescope (SST-1M) is one of several prototype SST designs. It will be equipped with a 4 m-diameter segmented mirror dish and a fully digital camera based on Geiger-mode avalanche photodiodes.
Currently, the first prototype of the mechanical structure is under assembly in Poland. In 2014 it will be equipped with 18 mirror facets and a prototype of the camera.
We report on the current status of the prototype and on the ongoing tests of the different components and the future plans.

Hobby-Eberly Telescope(HET) wide field corrector is a 4 mirror prime focus corrector to deliver 22 arcminute field of view and a 10 m pupil. The HET uses an 11-m fixed elevation segmented spherical primary mirror and the images created by the spherical primary mirror are aberrated with 13 arcmin diameter point spread function. Based on the design provided by the University of Texas, the University of Arizona has developed the 4-mirror wide field corrector to compensate the aberrations from the primary mirror. This paper presents the technical details of the alignment and system performance evaluation of the corrector using three CGH tests to ensure redundancy in alignment and performance.

The Maunakea Spectroscopic Explorer (MSE; formerly Next Generation Canada-France-Hawaii Telescope) is a dedicated, 10m aperture, wide-field, fiber-fed multi-object spectroscopic facility proposed as an upgrade to the existing Canada-France-Hawaii Telescope on the summit of Mauna Kea. The enclosure vent configuration design study is the last of three studies to examine the technical feasibility of the proposed MSE baseline concept. The enclosure vent configuration study compares the aero-thermal performance of three enclosure ventilation configurations based on the predicted dome thermal seeing and air flow attenuation over the enclosure aperture opening of a Calotte design derived from computational fluid dynamics simulations. In addition, functional and operation considerations such as access and servicing of the three ventilation configurations will be discussed.

We present the design, commissioning, and initial results of the Green Bank Earth Station (GBES), a RadioAstron data downlink station located at the National Radio Astronomy Observatory (NRAO) in Green Bank, West Virginia. The RadioAstron satellite carries a 10m space radio telescope and has a highly elliptical orbit extending to 350000km at apogee. While observing simultaneously with several ground telescopes, it forms Earth's longest radio interferometer. Data downlinks must be collected via large stations to provide sufficient gain for signal reception. The GBES was implemented to meet the need for an Earth station in the Western Hemisphere.

A one year database has been gathered of the VLT active optics Shack-Hartmann wavefront sensor images taken at each operating focus about every 30 seconds. A dedicated code insensitive to atmospheric dispersion was developed to accurately extract the median full width at half maximum of the unvignetted S-H spots.
The observing conditions simultaneously experienced inside each of the four 30m high VLT-UT enclosures are compared to each other and to the outside seeing measured at 6m above ground by the VLT Astronomical Site Monitor. The influence of wind speed and relative direction with respect to the direction of observation is analyzed.

We illustrate the status of the international infra-red telescope IRAIT-ITM, a project developed thanks to an Italian-Spanish-French collaboration and now sited at the Dome C Antarctic base. The camera Camistic equiped with a bolometer detector is used to test the sky stability during one year at fixed daily hours. The results in sky stability at 200 and 350 µm will be compared with other sub-millimeter sites.

Chinese Antarctic Observatory has been listed as National large research infrastructure during twelfth five-year plan. Kunlun Dark Universe Survey Telescope, one of two major facility of Chinese Antarctic Observatory, is a 2.5 meter optic/infrared telescope and will be built at the Chinese Antarctic Kunlun Station. It is intended to take advantage of the exceptional seeing conditions, as well as the low temperature reducing background for infrared observations. KDUST will adopt an innovative optical system which can deliver very good image quality over a 2 square degree flat field of view. All of parts of it have been designed carefully to endure the extremely harsh environment. KDUST will be perched on a 14.5-meter-high tower to lift it above the turbulence layer. In this paper, preliminary design and key technology pre-research of KDUST will be introduced.

The AST3 project consists of three large field of view survey telescopes with 680mm primary mirror, mainly for observations of supernovas and extrasolar planets searching from Antarctic Dome A. The first AST3 was mounted on Dome A in Jan. 2012 and automatically runned from March 2012. The second telescope is in Mohe site for the winterization observation. The technical modifications and testing observation results will be given in this paper. The third AST3 will be optimized from optical to thermal infrared aiming diffraction limited imaging with K band. The AST3 project will be a good test bench for the development of future larger aperture optical/infrared Antarctic telescopes .

The ALMA North America Prototype Antenna was awarded to the Smithsonian Astrophysical Observatory (SAO) in 2011. SAO and the Academia Sinica Institute of Astronomy & Astrophysics (ASIAA), SAO’s main partner for this project, are working jointly to relocate the antenna to Greenland to carry out millimeter and submillimeter VLBI observations, as well as single dish observations down to 200 μm.
In this paper we will present the work carried out on upgrading the antenna to enable operation in the Arctic climate by the GLT Team to make this challenging project possible, with an emphasis on the unexpected telescope components that had to be either redesigned or changed. We will then present the different steps to move the antenna to Greenland until final reassembly at Isi – a new scientific base, close Summit Station, operated by the US NSF.

We will present new results from the first search for transiting exoplanets undertaken from the High Arctic: the AWCam (Arctic Wide-field Cameras) survey. The ongoing survey, which has been operating for 2.5 years, is based at 80 degrees North on Ellesmere Island in the Canadian High Arctic. The small telescopes monitor 70,000 bright stars in a several-hundred square-degree region around Polaris, with milli-magnitude photometric precision, and are capable of discovering giant planets around 10,000 bright, nearby solar-type stars. We will present the first long-term monitoring results from the AWCams, including the first assessment of the transiting planet population around our bright, nearby target stars. We will also use the AWCam survey's experiences to assess the feasibility and challenges of performing long-term astronomical surveys at High Arctic observatories.

Planetary protection consists of the measurement and characterization of near earth objects including earth threatening asteroids and earth orbiting debris. The Lockheed Martin Advanced Technology Center in Palo Alto California is developing new astronomical instruments for use in planetary protection. We propose a ground based observatory instrument that is designed specifically for understanding the size, shape, and chemical makeup of the various orbital debris components that are currently orbiting earth in geosynchronous and nearby orbits including the geo-graveyard orbit where expended satellites are parked. We include observation scenarios using a 4 meter telescope designed for long wave infrared astronomy and currently operating on Mauna Kea.

The Lockheed Martin Advanced Technology Center has built a Space Object Tracking Facility (SPOT) at our Santa Cruz test facility in Northern California. The SPOT facility consists of three 1 meter optical telescopes on movable platforms, enabling both individual simultaneous collects with a variety instrument and sparse aperture interferometric imaging. The individual telescopes achieved first light in June 2012 and have been used since to observe numerous orbiting satellites and orbital debris. LM is implementing enhancements for the facility, which includes AO, fiber coupling and active fringe tracking, that will be coming on line from mid-2014 through late-2015.

Monday 23 JuneShow All Abstracts

Session PLMon:
Plenary Session

Monday 23 June 20148:50 AM - 10:00 AM
Location: Room 517d

Session Chair:

Luc Simard, NRC - Herzberg Institute of Astrophysics (Canada)

8:50 AM: WelcomeLuc Simard, National Research Council of Canada (Canada)

We will discuss the design and philosophy underlying the cryo-optical test program for the Observatory. Cryo-optical testing begins with the instrument complement at the Goddard Space Flight Center, and finishes with an end-to-end test of the assembled telescope in the world’s largest cryogenic vacuum chamber at the Johnson Space Flight Center. In the context of a detailed overview of JWST’s deployment steps after launch, we will describe the final stages of Observatory integration and the testing to verify these deployments, ready for launch. Finally, we will discuss the post-launch timeline to transition the stowed Observatory to the start of science operations.

The Square Kilometre Array is the next-generation radio-telescope. It will be a true mega-science facility. It is being designed and will be built by a global consortium, headquartered in the UK. The consortium currently has 11 member countries but is open for additional members at any time.
The SKA Observatory will have sites in Australia and South Africa, and will build on the two precursor telescopes, ASKAP and MeerKAT, currently under construction on the sites. The SKA is being designed as a physics machine for the 21st Century and will address scientific questions such as the nature of gravity, the origins of the Universe and the origins of life. I will describe the scientific rationale for the SKA; the technologies selected to deliver that science and the challenges posed in handling the massive data volumes to be generated by the observatory.
The SKA is now in the detailed design phase. Funding exceeding €120M has been committed by the partner nations to deliver that design. The design will be complete at the end of 2016 and, assuming construction funding is secured, the procurement process will begin in 2017 and construction in early 2018. The SKA will deliver early science by 2020.

CTA, the Cherenkov Telescope Array, is the next generation ground-based observatory for gamma-ray astronomy in the energy range from 20 to 300 TeV. The CTA project is finishing its preparatory phase, and the pre-production phase will start in 2014. The expected performance of CTA has been established using very detailed simulations. The physics cases for CTA were established and the key physics programs are defined. A report on the design and prototypes of the different telescopes will be given. Plans for array control, data acquisition and data management are well advanced and will be discussed. Several site candidates for CTA on the Southern and Northern were evaluated, and a site decision will be taken in the first month of 2014.

The Cherenkov Telescope Array observatory will represent the next generation of Imaging Atmospheric Cherenkov Telescope. Using a combination of large-, medium-, and small-scale telescopes, it will explore the Very High Energy domain from a few tens of GeV up to about few hundreds of TeV with unprecedented sensitivity, angular resolution and imaging quality.
In this framework, the Italian ASTRI program, led by the Italian National Institute of Astrophysics (INAF), is currently developing a scientific and technological SST prototype named ASTRI SST-2M. A 4-meter class telescope, it will adopt an aplanatic, wide-field, double-reflection optical layout in a Schwarzschild-Couder configuration.
In this contribution we give an overview of the technological solutions adopted for the ASTRI SST-2M prototype. In particular we focus on the manufacturing of the telescope structure and mirrors. We will also describe early results from the factory and in-house tests on the structure and mirrors.

ASTRI is a flagship project of the Italian Ministry of Education, University and Research. INAF is developing a wide-field-of-view end-to-end prototype of the Small-Size Telescope of the Cherenkov Telescope Array, for the energy band 5-100 TeV. ASTRI is based on a compact Schwarzschild-Couder optical design. This allow the adoption of an innovative camera based on SiliconPM. Following tests of ASTRI, the construction of a mini-array of 7 telescopes is planned (part of the CTA seed array), around which CTA will be developed. With the mini-array it will be possible to perform an early scientific program, e.g. the cut-off regime of cosmic accelerators. International institutes participate including INAF, South Africa North-West University and Sao Paulo University. Contributions from the Observatoire de Paris and Universities and Institutes in UK, The Netherlands, Japan and US are also foreseen. This talk will report the design, implementation and science goals of the SST mini-array.

CTA, the Cherenkov Telescope Array is the next generation ground-based observatory for gamma-ray astronomy in the energy range from 20 to 300 TeV. The sensitivity in the core energy range will be dominated by up to 40 Medium-Sized Telescopes. These telescopes, of Davies-Cotton type with a reflector with a diameter of 12m, are currently in the prototype phase. A full-size mechanical prototype with drive system has been constructed in Berlin. Different prototype mirrors have been developed, tested and are mounted on the prototype. Two camera types are designed and prototyped. Demonstrator cameras were built and are tested, the integration of these cameras on the prototype is prepared. A report on all aspects of the design, commissioning and performance of the Medium-Sized Telescopes and its main components will be given.

The Cherenkov Telescope Array (CTA) Large Size Telescope (LST) is
designed to achieve observations of high redshift objects with the threshold
energy of 20 GeV and is located at the center of the CTA array. The
gamma-ray horizon will be expanded up to redshifts of z = 2 for active
galactic nuclei (AGNs) and up to z = 4 for gamma-ray bursts (GRBs). LSTs
have a large mirror surface of 387 square meters and high resolution cameras with
high quantum efficiency (high-QE) photomultipliers. The total weight of the
telescope (70 tons) is minimized by the use of a lightweight structure and
this permits the fast rotation of the telescope in follow-up observations of
GRBs. The overall design and status of the telescope development will be
discussed.

SOFIA, the Stratospheric Observatory for Infrared Astronomy, has had three openly competed calls for General Investigator science. In this paper we describe the proposal process for SOFIA, including special tools used for the preparation of proposals. We also discuss lessons learned in the operation of the proposal calls. Finally, we include some science highlights from the General Investigator program.

The Balloon-borne Large Aperture Submillimeter Telescope for Polarimetry (BLASTPol) is a suborbital mapping experiment, designed to study the role played by magnetic fields in the star formation process. BLASTPol observes polarized light using a total power instrument, photolithographic polarizing grids, and an achromatic half-wave plate to modulate the polarization signal. During its second flight from Antarctica in December 2012, BLASTPol made degree scale maps of linearly polarized dust emission from molecular clouds in three wavebands, centered at 250, 350, and 500 μm. The instrumental performance was an improvement over the 2010 BLASTPol, with decreased systematics resulting in a higher number of confirmed polarization vectors. The resultant dataset allows BLASTPol to trace magnetic fields in star-forming regions at scales ranging from cores to entire molecular cloud complexes.

The original pointing stability (Image Jitter) goal of the Stratospheric Observatory for Infrared Astronomy SOFIA was defined at the beginning of the program in the late 1980ies as finally and very challenging 0.2 arcsec rms. As SOFIA approaches its full operation capabilities the telescope jitter is ~0.9 arcsec rms, which is sufficient for most of the SOFIA science instru-ments. The paper recollects the tools used in the different project phases for the verification of the pointing stability and gives hints for the planning of the upcoming 4 year program to bring the telescope jitter to its final performance.

We present the carbon-fibre-reinforced-polymer and aluminum structure designed for Spider, a balloon-borne telescope. Spider is designed to measure the polarization of the CMB radiation with unprecedented sensitivity and control of systematics. The Spider gondola is designed to house the telescopes and guarantee their operation during the balloon-borne flight taking less than 15% of the total mass of the payload. We present the gondola construction method and describe the design validation through FEA and mechanical tests. We describe the difficulties in the construction of this structure and establish landmarks which can be used in the design of future balloon-borne instruments.

We present the technology and control methods developed for the Spider pointing system. Spider is a balloon-borne polarimeter designed to detect a primordial gravitational wave signal in the polarization of the Cosmic Microwave Background. We describe the two components of the telescope's azimuth drive: the reaction wheel and the pivot. A 10 kHz PI control loop runs on a DSP, with feedback from rate gyroscopes. This system can control azimuthal speed with < 0.02 deg/s rms error. To control elevation, Spider uses stepper-driven linear actuators to rotate the cryostat and optical instruments relative to the outer frame. With the velocity in each axis so-controlled, higher-level control loops on the flight computers can implement specific pointing and scanning observation modes as required. We demonstrate the successful scanning of a 5000 lb payload sinusoidally in azimuth at a peak acceleration of 0.8 deg/s^2 and peak speed of 6 deg/s, while achieving sub-arcminute pointing accuracy.

We present the second generation BLASTbus electronics. The primary purposes of this system are bolometer readout and telescope attitude control. This requires low noise and parallel acquisition of many analog signals, as well as the capability to interface to a wide variety of sensors and motor controllers. To achieve these different purposes, the BLASTbus system employs a flexible motherboard-daughterboard architecture, with programmability from a DSP and FPGA. The BLASTbus is also used in thermometry, power, and cryogenic systems. For accurate timing, the system is fully synchronous. BLASTbus electronics have been deployed to the South Pole, and flown on stratospheric balloons.

The Stratospheric Observatory for Infrared Astronomy (SOFIA) uses three CCD cameras with different optics for target acquisition and tracking. An upgrade of these imagers is currently in progress. The new Focal Plane Imager (FPI) has been successfully integrated and the new Fine Field (FFI) and Wide Field Imagers (WFI) are currently in development. Andor iXon cameras will be used in all three imagers to significantly increase the sensitivity and the FFI and WFI will also receive improved optics with a temperature stable focus from ground to stratospheric temperatures. In this paper we will report on the results of the new FPI and the status of the FFI/WFI work.

A new test bench for detector and camera characterization in the visible and near-infrared spectral range has been setup and commissioned. The detector under study is illuminated by an integrating sphere that is fed by a Czerny-Turner spectrometer with quasi-monochromatic light. Si- and InGaAs-based photodiodes have been calibrated as secondary reference standards for precise spectral flux measurements between 350 and 2500 nm. The article will focus on the performance evaluation and characterization of two commercial camera systems with 640x480 InGaAs-detectors. Both cameras would allow ground-based and airborne astronomical observations or could act as tracking cameras in the NIR, e.g. on SOFIA.

Session PSMon:
Posters: Monday 9145

Monday 23 June 20145:30 PM - 7:00 PM
Location: Room 516
Authors should be prepared to display their poster at morning coffee break. Posters for this conference will be on display on Monday. The interactive poster session with authors in attendance will be Monday evening from 5:30 to 7:00 pm. Authors should remove their posters at the end of the poster session. Posters left displayed will be considered unwanted and will be discarded.

The 6-DOF parallel platform in this paper is a kind of Stewart platform. It is used as supporting structure for telescope secondary mirror. In order to adapt the special dynamic environment of the telescope secondary mirror and to be installed in extremely narrow space, a unique parallel platform is designed. PSS Stewart platform and SPS Stewart platform are analyzed and compared. Then the PSS Stewart platform is chosen for detailed design. The virtual prototyping model of the parallel platform is built. The model is used for the analysis and calculation of multi-body dynamics. With the help of ANSYS, the finite element model of the platform is built and then the analysis is performed. According to the above analysis the experimental prototype of the platform is built. The test of the prototype verified that the structure design of 6-DOF parallel platform for telescope secondary mirror is reliable and acceptable.

The Large Synoptic Survey Telescope (LSST) integration and test plan is phased to ensure that subsystems and services are available to support the integration flow. The approach is to favor all hardware mated and pre-tested at vendors prior to delivery onsite. The plan exploits the diffraction limited on-axis image quality of the three-mirror design. Fiducials will be used during optical acceptance testing at vendors to capture the optical axis geometry of each optical element. In this paper, we describe the major steps of the LSST telescope integration and test sequence until start of commissioning with the science camera.

The Large Binocular Telescope (LBT) has three pairs of Active Optics (aO) systems used to collimate the telescope. We will describe the aO systems and their uses at the various focal stations, discuss their similarities and differences, and evaluate and compare their operational performances (i.e. with guide stars having different distances from the optical axis and guide stars of various brightness). We will also describe their performance with differing seeing conditions.

Just as the 2.4 meter Automated Planet Finder (APF) commenced its final shakedown, three significant events occurred: uncontrolled telescope oscillations while tracking, liquidation of the telescope vendor's primary facility, and the expiration of the vendor warranty. Left with scant documentation, few external resources to draw upon, and limited direct local expertise, University of California Observatories (UCO) embarked on an initiative to stabilize the telescope control system at a minimal internal cost. This paper covers the problems encountered, our solutions, and the compromises made when the budget could not support a complete remedy.

A major upgrade of the HET is in progress that will substantially increase the pupil size to 10 meters and the field of view to 22 arc-minutes by replacing the spherical aberration corrector. The new Wide Field Corrector is a 4-element assembly weighing 750kg and measuring 1.34 meters diameter by 2.1 meter in length. Special fixtures were required in order to support the mirrors of the Wide-Field Corrector during the vacuum coating process. Design principles, materials, implementation details, as well as lessons learned are covered.

The Large Binocular Telescope active optic system uses measured mechanical deflection and analysis of stellar images to calculate optic displacements. A supplemental system is proposed would uses a laser tracker to measure optic misalignment. A single laser tracker location can be used to measure the locations of optical assemblies for both telescopes. A set of reference points assist with binocular copointing. The laser tracker measures the displacement of the optics relative to their locations measured when the telescope is in collimation. Practical considerations integrating the system with the telescope will be discussed, as well as it expected performance.

The Changchun Institute of Optics, Fine Mechanics and Physics (CIOMP) team is developing the Giant Steerable Science Mirror (GSSM) for Thirty Meter Telescope (TMT) which will get into the preliminary design phase in 2015. To develop the passive support structure system for the largest elliptic-plano flat mirror, the smoothest tracking mechanism for the gravity-invariant condition, CIOMP is designing and building a 1/4 scale, functionally accurate version of the GSSM prototype. The prototype system will be completed in the end of 2014 and provide the technical support to the preliminary design of GSSM.

At the LBT, collimation influences a number of optical control objectives including: pointing, coma, focus, focus field gradients, phase piston, phase piston field gradients, astigmatism field gradients, field rotation and more. Collimation algorithms currently in use control a limited set of these objectives and, as we move closer to interferometric operations, it becomes necessary to further constrain the positions of the optics. The authors have developed methods of finding the optimal collimation with limited feedback while also optimizing the mechanical ranges of the optical platforms. We discuss these methods and illustrate their application to the collimation controller currently under development.

Searching for nearby exoplanets with direct imaging is one of the major scientific drivers for both space and ground-based programs. While the second generation of dedicated high-contrast instruments on 8-m class telescopes is about to greatly expand the sample of directly imaged planets, exploring the planetary parameter space to hitherto-unseen regions ideally down to Terrestrial planets is a major technological challenge for the forthcoming decades. This requires increasing spatial resolution and significantly improving high contrast imaging capabilities at close angular separations. Segmented telescopes offer a practical path toward dramatically enlarging telescope diameter from the ground (ELTs), or achieving optimal diameter in space. However, translating current technological advances in the domain of high-contrast imaging for monolithic apertures to the case of segmented apertures is far from trivial.
SPEED - the segmented pupil experiment for exoplanet detection - is a new instrumental facility in development at the Lagrange Laboratory for enabling strategies and technologies for high-contrast instrumentation with segmented telescopes. SPEED combines wavefront control including precision segment phasing architectures, wavefront shaping using two sequential high order deformable mirrors (DMs) for both phase and amplitude control, and advanced coronagraphy struggled to very close angular separations (PIAA). SPEED represents significant investments and technology developments toward the ELT area and future spatial missions, and will offer an ideal cocoon to pave the road toward technological progress in both phasing and high contrast domains with complex/irregular apertures. In this paper, we will describe the overall design of this bench and will focus on the characterization of the two essential sub-systems: the segmented DM and the high-order continuous sheet DMs.

The CIDRE project aims to measure the transitions of the HD molecule in the THz band as well as other lines in our galaxy by an instrument carried by a stratospheric balloon to an altitude of about 40,000 meters.
Because of the stringent pointing requirements and of the extreme thermal environment due to the balloon borne trajectory, the mechanical structure had to be carefully designed. In this paper, we first describe the optical design and the mechanical composite structure of the instrument and then, the validation by finite element method of mechanical and thermal behaviors of the instrument.

The Stratospheric Observatory for Infrared Astronomy SOFIA is jointly operated and developed further by NASA and DLR to study the universe in the infrared spectrum. It consists of a Boeing 747SP aircraft, carrying a telescope with a 2.7 m primary mirror. The image stability goal for SOFIA is 0.2 arc-seconds rms. The performance of the telescope structure is affected by elastic vibrations induced by aeroacoustic loads. Active compensation of such disturbances requires a fast way of estimating the structural motion.
Integrated navigation systems (INS) are examples of motion estimation systems. However they employ a rigid body assumption. A possible extension of such integrated systems to an elastic structure is shown by different authors for one dimensional beam structures taking into account the eigenmodes of the structural system. Extending this mathematical approach to three dimensional structures, the aspect of a modal observer based on integrated motion measurement (IMM) will be simulated for SOFIA. IMM is in general a fusion of different measurement methods by using their benefits and blinding out their disadvantages. The kernel of the integrated system consists of a continuous-discrete extended Kalman filter estimating the modal states of the telescope structure: gyroscopes and accelerometers are used to obtain reliable signals with a good time resolution being complemented by strain gauges and focal plane image motion as long term reliable signals. Besides the sensor signals to be fused, a filter requires a kinematical model, which in turn determines the mechanical meaning of the measurements. The kinematical model is provided by a Finite Element structure and is additionally reduced using a modal approach. The reduced model aims at the target modes which have high contribution to the image jitter at the focal plane of the telescope.
There are no mass and stiffness properties needed directly in this approach. However, the knowledge of modal properties of the structure is necessary for the implementation of this method. A Finite Element model is also chosen as a basis to extract the modal properties of the structure. Hence the accuracy of estimation relies on the FE model of the telescope assembly, which is being updated using modern methods of parameter identification.

An attitude determination system for balloon-borne experiments is presented. The system provides pointing information in azimuth and elevation for instruments flying on stratospheric balloons over Antarctica. The multi-sensor system was employed by the Balloon-borne Large Aperture Submillimeter Telescope for Polarimetry (BLASTPol), an experiment that measures polarized thermal emission from interstellar dust clouds. A similar system was designed for the upcoming flight of Spider, a Cosmic Microwave Background polarization experiment. The pointing requirements and system performance for these experiments are discussed, as well as the challenges in designing attitude reconstruction systems for high latitude balloon flights.

New flight hardware for SOFIA has to be tested to prove its safety, functionality and required performance under flight conditions. To do this, an environmental test lab was set up. This paper gives an overview of the equipment, shows results from the commissioning and characterization of the thermal vacuum chamber, and presents examples of the component tests that were performed so far. To test the focus position stability at stratospheric temperatures, an auto-collimation device has been developed. Its design and results from measurements on commercial off-the-shelf optics as candidates for the new Wide Field Imager for SOFIA will be presented.

The vibration forces imparted by various types of operating equipment have been measured at existing observatories. Typical vibration surveys have measured only the motion (acceleration); however, the acceleration depends on both the source and the system being excited. Instead, here we consider the isolator properties combined with measured acceleration to infer the applied forces. These force estimates can then be combined with a model-based vibration transmission analysis for TMT in order to estimate the optical consequences.
We present a novel approach for measuring the force due to operating isolator-mounted equipment that is based on measuring the transfer function associated with the isolator, using this to estimate isolator characteristics (where otherwise unavailable), and combining this with the measured operating motion to infer the force at the base of the isolator.

BIRC is a multispectral imager designed to operate in 8 narrow bandpasses between 2.5 and 5.0 µm utilizing a cryo-cooled HgCdTe detector and 0.8 m diameter telescope. The instrument was flown on a balloon craft platform and operated in a near-space environment. BIRC was designed to measure the water and CO2 emissions from the comet ISON. The system produces an f/4 image over a field of view of 3 arcminutes, and leverages shift+coadd algorithms to observe dim objects. An innovative thermal design holds the system components in separate vacuum and atmospheric zones which are independent of the neighboring instrument deck. This paper summarizes the design, test and integration of the BIRC instrument.

The Cherenkov Telescope Array (CTA) observatory will be the biggest ground-based very-high-energy (VHE) γ-ray observatory. The CTA observatory will be capable of issuing alerts on variable and transient sources to maximize the scientific return. To capture these phenomena during their evolution a Real-Time Analysis (RTA) pipeline will be developed, a key system of the CTA observatory.

Compensating the effects of structural vibrations in the optical path will be a major design question for adaptive optics (AO) systems in future extremely large telescopes. A promising control system architecture is the recently developed “Dual-Loop-Approach”, with a feedforward loop based on accelerometer measurements, compensating for the vibrations in addition to the classical AO feedback loop. We present our efforts to develop sophisticated estimation and control algorithms for this feedforward loop. The algorithms are evaluated and compared using a realistic Tip-Tilt-Vibration laboratory test setup. Position renconstruction for a realistic 8 Hz structural resonance with an error of only 4 % is achieved.

The Atacama Large Millimeter/Submillimeter Array (ALMA), located on the Chajnantor plateau at 5000 meters altitude in northern Chile, is being constructed in an international collaboration. ALMA consists of 54 twelve-meter antennas and 12 seven-meter antennas operating as an aperture synthesis array in the (sub)millimeter wavelength range.
The ALMA Band 10 receiver covering 787 to 950 GHz is the highest frequency receiver of the ten bands envisioned for the ALMA Front End system. The Band 10 receivers have been undergoing installation and commissioning at ALMA since 2012.
After the Band 10 receiver tuning scripts and operation procedure had been developed and implemented at ALMA,
astronomical verification procedures (radio pointing, focus, beam squint, and end-to-end spectroscopic verification)
were established in single dish mode at the ALMA Operations Support Facility. Subsequently, the first Band 10 astronomical fringes were achieved at the Array Operations Site in October 2013.

The Observatoire de Paris is involved in the Cherenkov Telescope Array (CTA) project by designing and constructing on the site of Meudon a Small Size Telescopes prototype, named SST-GATE. This telescope is based on the Schwarzschild-Couder optical formula which has never been adopted before in the design of a Cherenkov telescope, and which allows a larger field of view (up to 10°) and cheaper and smaller size telescope and camera.
The SST-GATE telescope has been designed with the prime objectives of being light, versatile, simple to assemble and with a minimal maintenance cost. This papers aims to review the SST-GATE telescope structure from mechanics to the control command architecture and the innovative developments implemented within the design, an update of the project status will be made.

We have developed a radio-holography receiver for ALMA antenna surface measurement. Key features of the holography receiver are an athermal endoskeleton structure, an external photonic local oscillator, a reduced number of high-frequency analog parts, and the introduction of a highly digitized processing system. Measured rms surface error of the 7-m antenna is better than 4.4 micro-meters, the repeatability is better than 2 micro-meters. The antenna deformation strongly depends on ambient temperature and Sun exposure. The result of the measurement which shows the surface panel rose up during the daytime. We also discuss the diurnal antenna surface deformation.

The Cherenkov Telescope Array is an international collaboration that aims to create the world's foremost Very High Energy gamma-ray observatory, composed of large, medium and small sized telescopes (SST). The SSTs will be the most numerous in order to capture the rarer highest energy photons.
Two prototypes of SST, ASTRI and SST-GATE, have been designed, based on a novel dual-mirror Schwarzschild-Couder (SC) design that allows for a smaller plate scale and therefore less expensive camera.
Both projects aim to demonstrate the mechanical feasibility and the optical performance achievable with this new structure for a lower cost than the traditional Davies-Cotton designs. After a discussion on the promising optical performance of SC telescope, we will report progress of both prototypes and theirs cameras (ASTRI and Compact High Energy Camera from UK/US/Japan/Netherlands team).

In Atacama Large Millimeter/submillimeter Array (ALMA) commissioning and science verification (CSV), we have investigated a feasibility of antenna Fast Switching (FS) phase calibration method for long baseline observations. We found that the ALMA interferometer phases become stabilized even for baselines longer than several hundred meters. We consider that the FS+Water Vapor Radiometer phase calibration is promising.

The southern part of the Cherenkov Telescope Array (CTA) observatory will consist of at least three types of telescopes: large size, medium size and small size telescopes. Monte Carlo simulations have been performed to analyze the performance of this array. We present the results of these simulations for a sub-array of small size telescopes of the Davies-Cotton type. Such a telescope, called SST-1M, is currently being proposed for the CTA observatory by a consortium of Polish, Swiss and German institutions. SST-1M will have a mirror of 4m diameter and it will be equipped with a fully digital camera based on silicon photodetectors. The analysis of the sub-array will be presented to demonstrate the fulfillment of the requirements of the CTA Consortium.

The FlashCam project is preparing a camera prototype around the fully digital FADC-based FlashCam readout system, for the medium sized telescopes of the Cherenkov Telescope Array (CTA). The FlashCam design is the first fully digital readout system for Cherenkov cameras, based on commercial FADCs and FPGAs as key components for the front-end electronics modules. By now, a 144-pixel "mini-camera" setup, fully equipped with photomultipliers, PDP electronics, and digitization/trigger electronics, has been realized and extensively tested. Preparations for a full-scale, 1764 pixel camera mechanics and a cooling system are ongoing. The paper describes the status of the project.

The Giant Magellan Telescope (GMT), one of several next generation Extremely Large Telescopes (ELTs), is a 25.4 meter diameter altitude over azimuth design set to be built at the summit of Cerro Campanas at the Las Campanas Observatory in Chile.
This paper describes the current status of the GMT enclosure structural and mechanisms design as it evolves in the current detailed design phase.

The Giant Magellan Telescope (GMT), one of several next generation Extremely Large Telescopes (ELTs), is a 25.4 meter diameter altitude over azimuth design set to be built at the summit of Cerro Campanas at the Las Campanas Observatory in Chile. The paper describes the use of Building Information Modeling (BIM) for the GMT project.

Development of extensive air showers at two different levels of measurement
Paper 9145-113
Time: 5:30 PM - 7:00 PM
Author(s):

The HAWC observatory is located 4100 meters above sea level on the northern slope of the volcano Sierra Negra, Mexico and will have sensitivity to gamma ray sources between 10 GeV and 100 TeV across two thirds of the entire sky. The LAGO experiment is capable to detect showers produced by gamma photons with energies ranging from 1 GeV to 100 TeV. It is located at 4600 m altitude, on the top of Sierra Negra. Both experiments have a linear separation of ~1.1 km in distance and 500 m in height, providing an exceptional opportunity to collect joint simultaneous information of showers. CORSIKA, one of the most used simulation programs for extensive air showers, was used to perform simulations of protons primaries with energies of 5 TeV onwards, so that the same shower can be detected by both experiments. We present rates resulting from simulations for each secondary particle type and we compare them with actual data taking with both observatories at their two different locations.

The Cherenkov Telescope Array (CTA) is the next major ground-based observatory for gamma-ray astronomy. CTA will utilize Imaging Atmospheric Cherenkov Telescopes (IACTs) to study gamma-ray sources in the energy range of a few tens of GeV to 100 TeV with up to ten times better sensitivity than currently available. We give a status report of the CTA project and discuss the planned US contribution to CTA which includes IACTs with Schwarzschild-Couder (SC) optics. The SC telescope provides a wider field of view, improved imaging resolution, and allows for the use of smaller pixel sizes than conventional IACTs. We will report on the status of the development of the SC telescope prototype. The progress in both the optical system and camera development will be discussed.

The telescope of the University of Tokyo Atacama Observatory has a 6.5m primary mirror in diameter. In order to fabricate the reflecting film initially and to maintain its performance over a long period, we have mirror coating facility on site. The facility consists of a clean booth for stripping off the old film, an evaporation coating chamber, and a cart with a lifter for handling the primary mirror. A conventional evaporation system with a metal pre-wetted filament array is adopted for achieving various optical requests. The coating equipment has also a function of fabrication for film on secondary and tertiary mirrors.

We present the thermal model of the Balloon-borne Large-Scale Submillimeter Telescope for Polarimetry, BLASTPol. This instrument was successfully flown in in 2010 and again in 2012; both were circumpolar flights from the McMurdo Base in Antarctica. We introduce the thermal design of the payload including the sun-shielding strategy. We present the in-flight thermal performance of the instrument and compare the predictions of the model with the temperatures registered during the flight. We describe the difficulties of modeling the thermal behavior of the balloon-borne platform and establish landmarks which can be used in the design of future balloon-borne instruments.

As a result of its wide field of view, the LSST optical system is unusually susceptible to stray light; consequently besides protecting the telescope from the environment the rotating enclosure (dome) also functions as an indispensible light baffle system. All the dome vents are covered with light baffles which simultaneously provide both exceptional dome flushing and stray light attenuation. The slits wind screen also functions as a light screen and only provides a minimum clear aperture. Since the dome must operate continuously, the drives are located on the fixed lower enclosure to facilitate glycol water cooling.

A basic design of an enclosure and support facilities for the University of Tokyo Atacama observatory (TAO) 6.5-m telescope is described in this paper. The enclosure has a Carousel shape and rotates independently of the telescope. A horizontally opened slit, a dozen ventilation windows, and an overhead bridge-crane are equipped. For safety reasons, most of maintenance passages are placed inside of the enclosure. Thermal insulation and low emissivity materials are used on the wall and the inside air is exhausted forcibly by fans. They provide excellent performance of dome seeing because the telescope temperature quickly follows that of outside air.

We have developed a 30-cm submillimeter-wave telescope intended to survey the Milky Way in 500GHz emission lines at the Dome Fuji station in Antarctic plateau. Transportability and low power consumption are required to the telescope for the operation in Antarctica. The telescope is designed to be divided into five components and to operate with less than 2.5 kW of electric power. We developed a low-nose receiver based on the ALMA Band 8 mixer unit with the smallest GM refrigerator. The motion of the telescope is demonstrated under -30°C condition. The operation will be started at Dome Fuji in 2015.

The Antarctica Search for Transiting Exo-Planets (ASTEP) program has completed its fourth observing winter with the 40cm ASTEP 400 telescope. Located on the Concordia Station on the Antarctic high plateau (Dome C), it benefits from about 4 months of almost complete darkness in the visible wavelength (R-band), an ideal situation for time-series observations, and particularly for exo-planet transit detection and characterization. In this poster, we cover the main results of the program, both from scientific and technical points of view. In particular, we address the question of the thermal stability of our telescope, its effect on the images and on the photometric quality.

SKA is a radio telescope that will have a receiving surface of a square kilometre. The Mid frequency range receivers of SKA will be located in the Karoo desert in South Africa. Several designs of housings are proposed to protect the antenna arrays and receivers to the harsh environment. Thermal analysis by Computational Fluid Dynamics are performed on the different designs of antenna housings to determine their effect on the maximum temperatures and the temperature stability of the receivers.

The second Antarctic survey telescope has been built in 2013 and tested in the north of China. The telescopes can point and track autonomously both in the summer and winter of the Antarctic. Firstly the article introduces the general structure of the second AST(Antarctic Survey Telescope), Secondly the relative displacement of the primary mirror and the corrector mirror has been calculated in the article. Thirdly the article analysis the system of the axes of the AST3-2 and the nature vibration frequency of the telescope is shown in the article. Finally, the package cushioning design and dynamics analysis of the telescope is discussed.

The Sardinia Radio Telescope (SRT) Metrology Team is planning to install a first set of sensors on the new 64m-diameter reflector antenna and to arrange a preliminary control system able to monitor the antenna performances by measuring the deformations of telescope components. In this article we will present the first series of measurement we made with an inclinometer we have chosen to integrate in the SRT framework. We performed different kind of measurements, to map the antenna rail planarity, to measure the azimuthal axis inclination and to monitoring the alidade thermal gradient effects on the pointing error performances.

Korea Astronomy and Space Science Institute (KASI) are under development of a wide-field photometric observation system, called Korea Microlensing Telescope Network (KMTNet) of which primary scientific goal is to discover extrasolar planets using the gravitational microlensing technique. The system consists of three 1.6 meter wide-field optical telescopes, each providing a 2.0 by 2.0 square degree field of view with a mosaic CCD camera of 18k by 18k pixels, and will be installed at three southern observatories, CTIO in Chile, SAAO in South Africa, and SSO in Australia by 2014. The optical configuration of the KMTNet telescope is prime focus, having a wide field corrector and the CCD camera on the topside of Optical Tube Assembly (OTA). The corrector is made of four lenses designed to have all spherical surfaces, being the largest one of 552 mm physical diameter. Combining with a purely parabolic primary mirror, this optical design makes easier to fabricate, to align, and to test the wide field optics. The centering process of the optics in the lens cell was performed on a precision rotary table using an indicator. After the centering, we mounted four large and heavy lenses on each cell by injecting the continuous Room Temperature Vulcanizing (RTV) silicon rubber bonding via a syringe. We present the design, assembly, alignment and verification process of the wide field corrector.

We present a project aimed to design and develop new technologies for the
observation of the sky at low radio frequencies. The goal is the installation at the Sardinia
Radio Telescope site of an aperture array constituted by about 128 prototypical low-frequency antennas designed to operate in the frequency range 70 - 450 MHz. The plan is to deploy an aperture array composed by a core station plus a few satellite stations. Each station is made by several dual-polarized Vivaldi antenna elements plus receiver chains which can be arranged in a regular or random pattern on the ground.

We present the status of the LAM/Thales SESO stress polishing demonstrator for the M1 E-ELT 1.5m segments. The warping harness, designed and optimised by finite element analysis, has been manufactured, integrated, assembled with a Zerodur segment and equipped with monitoring devices. An approach based on influence function measurements and eigenmodes calculation leads to the optimal shape that can be reached by the system. Results of the full bending of the mirror will be presented as well as the status of the polishing. Last part of the presentation will be dedicated to the industrialization of the process by Thales SESO.

Optical system performances can be affected by local optical turbulence created by its surrounding environment (telescope dome, clean room, atmospheric surface layer). We present a new instrument INTENSE (INdoor TurbulENce SEnsor) dedicated to this local optical turbulence characterization. INTENSE consists of using several parallel laser beams separated by non redundant baselines between 0.05 and 2.5m and measuring Angle-of-Arrival (AA) fluctuations from spots displacements on a CCD. We present detailed characterization of instrumental noise and first results for the characterization of the turbulence inside clean rooms for optical testing and integration.

The QUIJOTE-CMB experiment (Q-U-I JOint TEnerife) is a project to obtain polarization measurements of the sky microwave emission in the 10-47GHz range. A couple of 2,5m telescopes and three instruments will operate at the Teide Observatory (Canary Islands). The first telescope and instrument (The MFI: Multi Frequency Instrument) are operating in the 10-18GHz band. The second telescope and instrument (TGI: Thirty GHz Instrument) will be in commissioning during summer 2014, covering the 26-36 GHz range. Finally, the Forty GHz Instrument will complete the sky survey in the frequencies 37-47GHz. This contribution is an overview of the whole technical project.

A particular example of a meter class flat mirror is the adaptive M4 unit of E-ELT, a deformable six petals Zerodur shell of 2.4 m in diameter. We studied the different approaches to the calibration and certification of M4, in a trade-off between stitching and full aperture measurements. We considered a beam expander setup, to test the mirror at normal incidence with a macro-stitching concept. Setups with different collimating mirrors and nulling lens systems, both on-axis and off-axis, have been studied to understand performances and sensitivities to fabrication errors, alignment errors and environmental effects.

The Sardinia Radio Telescope (SRT) is a fully steerable antenna with a Gregorian optical configuration that should be maintained with an alignment accuracy of about a tenth of millimeter in order to guarantee the optimal antenna pointing and efficiency. Among them we installed a PSD (Position Sensing Device) that coupled with a laser diode source is able to measure the antenna secondary mirror (M2) displacements and tilts. In this paper we will describe in details the mechanical system we made to align the PSD and the laser diode and install all of them in the antenna framework.

The Canadian Hydrogen Intensity Mapping Experiment (CHIME) is a transit interferometer to be located at the Dominion Radio Astrophysical Observatory. We will use CHIME to map neutral hydrogen between 400-800MHz over half of the sky, producing a measurement of baryon acoustic oscillations (BAO) at redshifts between 0.8 -- 2.5 to probe dark energy. We have deployed a pathfinder version of CHIME that will yield tighter constraints on the BAO spectrum and provide a testbed for our calibration scheme. I will discuss the current calibration status and describe instrumentation we are developing to meet the calibration requirements for CHIME.

We summarize the design and the current fabrication status for the TAO 6.5-m telescope. The telescope is
optimized for infrared observations and the pupil is set at the secondary mirror. It has two Nasmyth and several
folded-Caseggrain foci with F/12.2. The mechanical and optical designs are done by following and referring to
those of the Magellan telescopes, MMT, and LBT. The F/1.25 bolosilicate light-weighted honeycomb primary
mirror is actively controlled by the realtime wavefront measurement system. The telescope mount, control
software design and error budget which defines the specification of stellar images are also described.

Extremely Large telescopes with more and more large apertures are pursued, proposed and constructed by astronomers and technicians all over the world in the coming next years to satisfy the great demand of scientific progress. Segmented mirror active optics is the most important technology to co-phase the large primary for optically perfect segmentation. Based the experimental platform and test work in Nanjing Institute of Astronomical Optics and Technology in China, we introduce the latest co-phasing progress on fine segment support, edge sensor and close-loop co-phasing correction in China in this paper. Finally some conclusions are given based on the test results.

Over the past two years, the Astronomical Society of New York and its institutional members have pursued further development of the 12 meter segmented optical telescope last presented at SPIE, Amsterdam in 2012. Four industrial studies have been performed addressing the facility, dome, telescope mount, and optics. Additional design detail and initial analyses are presented and an update to the cost estimate and schedule for development are provided. The NYSO is conceived as a telescope for all New York based institutions performing astronomical research and is intended for general astronomical research.

We report on the first test results of the on telescope testing of the newly developed inductive edge sensing system pioneered by Fogale Nanotech. The sensors are installed on the central seven segments and evaluated using a Shack-Hartman sensor at the centre of curvature. Also presented are the environmental verification tests performed during the evaluation and characterisation of the sensors.
The sensors have to be supported on the underside of the segments and therefore require an innovative mounting solution allowing for fixed sensor separation and adjustment for segment misalignment.

In this paper we present an analysis of the statistical and temporal properties of seeing and isoplanatic angle measurements obtained with combined Differential Image Motion Monitor (DIMM) and Multi-Aperture Scintillation Sensor (MASS) at Jbel Aklim candidate site for the Eauropean Extremely Large Telescope (E-ELT).
These data have been collected from February 2008 to Jun 2010. The overall seeing statistics at Jbel Aklim site are presented, broken into total seeing, free atmosphere seeing and isoplanatic angle, and ground-layer seeing (difference between the total and free-atmosphere seeing). We examine the statistical distributions of seeing measurements and investigate annual and nightly behavior.
The properties of the seeing measurements are discussed in terms of the geography and meteorological conditions at Jbel Aklim site.

The new Extremely Large Telescope projects need accurate evaluation of the candidate sites. In this work
we present the seeing, free seeing and isoplanatic angle comparison between Aklim site located in Moroccan Anti-Atlas at the geographic coordinates 30°7'39" N, 08°18'39" W, and the Observatorio del Roque de Los Muchachos (ORM), located in La Palma, Canary Islands, at 28°45'00 N, 17°53''10 W, the both sites are pre-selected to house the E-ELT.
In this work we present the total seeing statistics, the free seeing and the isoplanatic angle measurements at each site, statistics of the mentioned parameters are obtained from the whole data recorded from 09 May 2008 to 09 November 2009 using the Multi Aperture Scintillation Sensor (MASS) - Differential Image Motion Monitor (DIMM) system,
compare the common data between the tow sites, more representative results and statistics are shown herafter

Edge sensor is one of the most important technologies for the extremely large segmented primary telescopes like Keck, Thirty Meter Telescope, European Extremely Large Telescope, etc. Different from the capacity edge sensor from Keck and TMT, one kind of an inductance edge sensor is proposed with the similar principle and configuration, fine aligned and tested in this paper to realize the same co-phasing maintenance purpose and high accuracy. The sensor is also sensitive to dihedral angle between the neighboring segments. Finally some preliminary conclusions are reached.

We present first results of a new instrument, the Generalized Differential Image Motion Monitor (GDIMM), aiming at monitoring parameters of the optical turbulence (seeing, isoplanatic angle, coherence time and outer scale). GDIMM is based on a small telescope equipped with a 3-holes mask at its entrance pupil. It is a compact and portable instrument, and can be remotely controlled by an operator. First results and cross-calibration with the Generalized Seeing Monitor (GSM) are presented in this paper.

The PICARD program included a space and a ground component set up at the Calern site of the Observatoire de la Côte d’Azur. During the last 4 years, the PICARD space mission has been used for observing the apparent solar diameter. First results of the PICARD astrometry program include a study of the June 2012 Venus transit for solar diameter determination. From this, the value of the solar radius from one astronomical unit was found to be equal to 959.86 arsec at 607.1 nm. However, concerning observed variations in time of the solar radius, instrumental effects affect the results. Space is known to represent a harsh environment for optical instruments. Nevertheless, we can use the PICARD ground data to monitor the solar radius variation. Several ground solar images at different wavelengths have been recorded since May 2011. This paper presents solar radius measurements obtained with PICARD.

Future extremely large telescopes will certainly be equipped with wide-field adaptive optics (AO) systems. However, performances optimization of these techniques require a precise specification of the different components in the AO systems. Most of these technical specifications are related to the atmospheric turbulence parameters, particularly the profile of the refractive index structure constant C2N(h). A new monitor called Profiler of Moon Limb (PML) for the extraction of the C2N(h) profile with high vertical resolution is presented. Emphasis was made on inversion techniques to retrieve C2N(h) profile and on noise errors propagation in the different stages of the data processing.

We present the phase characteristics study of the ALMA 3 km baseline data. We successfully obtained the spatial structure function of phase fluctuation, which increases as a function of baseline length up to 1.0-1.5 km, and turns to be almost flat at longer baseline. This is the first mm/submm structure function to show the turn-over of the structure function. Furthermore, confirmation of the turn-over indicates that even the ALMA baseline length extended to the planned longest baseline of 15 km, the fringe will be detected at the similar rms phase fluctuation as that at a few km baseline lengths.

The Chinese Giant Solar Telescope (CGST) is the next generation solar telescope of China with diameter of 8 meter. The unique feature of CGST is that its primary is a ring, which facilitates the polarization detection and thermal control. In its present design and development phase, two primary mirror patterns are considered. For one thing, the primary mirror is expected to construct with mosaic mirror with 24 trapezoid (or petal) segments, for another thing, a monolithic mirror is also a candidate for its primary mirror. Both of them depend on active control technique to maintain the optical quality of the ring mirror. As a solar telescope, the working conditions of the CGST are quite different from those of the stellar telescopes. To avoid the image deterioration due to the mirror seeing and dome seeing, especially in the case of the concentration of flux in a solar telescope, large aperture solar projects prefer to adopt open telescopes and open domes. In this circumstance, higher wind loads act on the primary mirror directly, which will cause position errors and figure errors of the primary with matters worse than that of the current 10-meter stellar telescopes with dome protect. Therefore, it gives new challenges to the active control capability, telescope structure design, and wind shielding design. In this paper, the active controls of the CGST for its mosaic mirror and monolithic mirror are presented, and the wind effects on such two primary mirror patterns are also investigated.

The Earth’s polar regions offer some special advantages for ground-based astronomical observations, including cold, dry conditions, combined with long periods of darkness, and the potential for unsurpassed image quality. We present results from a site-testing campaign during nighttime from October to November 2012 at the Polar Environment Atmospheric Research Laboratory (PEARL), on a 610-m high ridge near the Eureka weatherstation on Ellesmere Island, Canada. A Shack-Hartmann wavefront sensor was employed, using the Slope Detection and Ranging (SLODAR) method. This instrument (Mieda et al, this conference) was designed to measure the altitude, strength and variability of atmospheric turbulence, in particular for operation under Arctic conditions. First SLODAR results are compared to simultaneous (previously reported) seeing measurements with differential image motion monitors. A discussion of implications for the design and performance of astronomical imaging systems follows.

SST-GATE (Small Size Telescope - GAmma-ray Telescope Elements) is a 4-metre telescope designed as a prototype for the Small Size Telescopes (SST) of the Cherenkov Telescope Array (CTA). More than a prototype, SST-GATE is also a fully functional telescope that shall be usable by scientists and students at the Observatoire de Meudon for 30 years. The Telescope Control System (TCS) is designed to work either as an element of a large array driven by an array controller or in a stand-alone mode with a remote workstation.
In this paper, we focus on three items: the pointing computation implemented in the FPGA of the cRIO — using CORDIC algorithms — since it enables an optimisation of the hardware resources; data flow management based on OPC UA with its specific implementation on the cRIO; and the use of an EtherCAT field-bus for its ability to provide real-time data exchanges with the sensors and actuators distributed througout the telescope.

Turbulence and temperature fluctuations in the atmosphere disturb the light path and affect the quality of astronomical images. In ground-based observational astronomy, characterizing atmosphere quality at observation site is crucial. The SLODAR (SLOpe Detection and Ranging) method uses a simple Shack-Hartmann wavefront sensor to measure vertical atmospheric profiles by observations of a binary system. In this paper we discuss the principle of the SLODAR method, the design of the instrument, and the performance testing in the lab. We developed this SLODAR instrument to do the site testing for the Canadian High Arctic Ellesmere Island in October/November 2012 (Maire et. al., this conference).

The purpose of the calibration systems is to consistently and accurately measure the observatory instrumental response and the atmospheric transparency during LSST observing. The instrumental response calibration will be performed regularly to monitor any variation of the transmission during the duration of the survey. The atmospheric data will be acquired nightly and processed to atmospheric models. In this paper, we describe the calibration screen system that will be used to perform the instrumental response calibration and the auxiliary telescope dedicated to the acquisition of spectral data to determine the atmospheric transmission.

Stellar Observations Network Group, SONG, is a Danish led project to construct a global network of small 1m telescope around the globe. The first telescope designed by CHINA is now installed and adjusted at Qinhai observation station in west CHINA. TCS has many motors to control, including direct drive azimuth and altitude axis, field of view derotation, M3 mirror rotation and location, atmosphere dispertion correction.The system hardware is based on PC and UMAC controller. The system software is developed in QT4 IDE under Debian linux operating system. Different tracking algorithms are studied according to different accuracy and velocity demand. The complicated communication between TCS and OCS has been realized. The TCS also has reliable safe protection and failture diagnosis function.

Telescopio Nazionale Galileo (TNG) is a 4m class active optics telescope at the observatory of Roque de Los Muchachos. In the framework of keeping optimum performances during observation and continuous reliability the telescope control system (TCS) of the TNG is going through a deep upgrade after nearly 17 years of service. The original glass encoders and bulb lamp heads are substituted with modern steel scale drums and scanning units. The obsolete electronic racks and computers for the control loops are replaced with modern and compact commercial drivers with a net improvement in the tracking error RMS. In order to minimize the impact on the number of nights lost during the mechanical and electronical changes in the TCS the new TCS is developed and tested in parallel to the existing one and three steps will be taken to achieve the full upgrade. We describe here the first step affecting the mechanical derotators at the nasmyth foci.

Reliability-Centered Maintenance (RCM) methodology is adopted by EIE Group to generate maintenance programs for ground-based large optical and radio telescopes, in parallel with a great effort made by designers the to obtain a maintainable telescope since the very first phases of the projects.
RCM aims to establish the complete maintenance regime with the safe minimum required maintenance, carried out without any risk to personnel, telescope and subsystems, increasing cost effectiveness and telescope uptime.
A parallel maintenance concept is to design and install LRU components in such a manner as to restore a failure and to perform servicing procedures as close as possible to the telescope.

To conduct astronomical observations during windy days and increase the time available for exploration with the Green Bank Telescope (GBT) it is necessary to reduce the sensitivity of the telescope structure to wind forces. A promising approach is to design advanced robust control system for wind induced vibration attenuation. As a first step it is necessary to (1) model analytically the structure and the servo system of the telescope and (2) validate the model through systems identification experiments. This paper presents the results of the identification experiments of the structure and the servo system along with the subsequent interval analysis.

A wavefront coded imaging system is an optical-digital method for aberration control. Wavefront coding (WFC) technology incorporates an aspheric element in the optical system in order to capture a coded image and by digital processing decode it to obtain the final image. The WFC system is very insensitive to defocus-like aberrations and thereby becomes a tool in the aberration balancing for telescope systems. We propose WFC technology to be implemented in a two spherical mirror telescope. In this work we present the design and simulation of the proposed telescope, trade-offs encountered in the design process and aspects of the image restoration.

This paper outlines an anti-cogging methodology and summarizes the current state of motor cogging cancellation on the Green Bank Telescope (GBT). An iterative, model-based algorithm is developed for finding the anti-cogging motor input signal. The algorithm develops a harmonic model of the system, negating any need for additional system identification. Use of this model for determining the anti-cogging solution yields rapid convergence. This method serves as a drop-in solution that works with existing feedback control systems. Results and implementation experience from deploying the algorithm on a motor test-bed and on the GBT are discussed.

Due to low absorption and negligible nonbirefringent character in atmosphere, optical free space therefore serves as the most promising channel for large-scale quantum communication by use of satellites and optical ground sations. This paper describes the equipment and features of the 1.2m astronomical telescope which will perform experiments with quantum experiment satellite of china. The telescope has coarse and fine loop, it controls a transmitting and receiving laser beam within a few micro radians jitter. The optical ground station uses 1.2m gimbaled telescope to collect the photons, the stragegy of the system is slightly developed to meet the need of tracking LEO satellite. This telescope with multiple functions will play an improtant role in space-to-ground communication.

This paper presents three optical designs based on the work of Maurice Paul. Paul's three-mirror anastigmats produce well-corrected, distortion-free fields of view. His design equations can be solved for a spherical primary mirror with one limitation: the image field is curved. Adding all-spherical refractive field-flattening optics yields well-corrected, flat image-fields of two degrees angular diameter or more. These designs can be scaled to very large telescopes with current technology.

CFHT has upgraded its telescope control system using the COTS PowerPMAC from Delta Tau as its motion controller. We use a special profiler available in the PMAC named "PVT" which stands for "Position-Velocity-Time". In this mode one constrains the final position, final velocity, and time the motion shall take to complete. From a real-time VxWorks machine we receive commanded positions for where the telescope shall be pointing at a 20Hz rate. The motion controller matches this rate by setting up each PVT move to last a duration of 50ms (one 20Hz period). The problem comes from the fact that each computers clock is inaccurate to some degree. Over the course of an hour we see the timing relative to one another drift by as much as 1/3rd of a second. To overcome this, on the motion controller, we measure the arrival time of the commanded messages and compare it to the completion of each 50ms motion program. If the completion of the motion program is beginning to lag behind the commanded messages then on the next motion the motion period is adjusted to finish slightly earlier (and vise-versa), thus keeping the two clocks in sync.

Non-common path aberrations (NCPAs), which take place downstream of the AO system, are well-known to be the primary impediment to ground-based ultra-high contrast imaging for exoplanet studies. A previous paper (ApJ 767, id.21) recently established the possibility of combining the wave-front sensor data stream with millisecond exposures in the science camera to simultaneously estimate the scene and the NCPAs. However, this work did not consider the degradation of the performance of the method from detector readout noise. Here, we consider the effect of readout noise on the ability to estimate time-dependent NCPAs (including vibrations) and the scene.

The Keck I and II telescopes have been operational respectively since 1990 and 1996. Operational improvements are sought to decrease the settling time in response to short moves. As part of this work the structural response of the open loop system has been re-identified. The mount control design was re-examined, and changes to the mount control architecture have been proposed in order to achieve improved response. Results from these studies are presented, both theoretical and experimental.

SONG (Stellar Oscillations Network Group) is a Danish initiative to design and build a global network of 1-m class telescopes, which plans to design and build a global network of small telescopes located at 8 existing observatories around the world. China SONG, as one of the eight sites, its 1-m class telescope can achieve the goal for long time continuous, uninterrupted, full automatic observation and works in the diffraction limit condition. At the same time the telescope must realize 0.2 arc second tracking precision without guide star, which is a very challenge and difficult task for 1 meter telescope tracking system . The direct drive motors and encoders form together with the control system a high performance telescope exhibiting very high tracking accuracy. This paper describes the integration and fine-tuning of the China SONG Drive Systems. It discusses the different problems encountered during the integration. The servo model that was used to simulate the problems and to find

The Cherenkov Telescope Array project aims to create the next generation Very High Energy gamma-ray telescope array made of three different classes of telescopes including Small Size Telescopes (SSTs).
Some of the sites considered for CTA exhibit strong seismic constraints. The Observatoire de Paris developed in collaboration with Durham University a mechanical design for a SST prototype named SST-GATE. This paper presents the seismic analysis of SST-GATE telescope and the application to the telescope of techniques issued from civil engineering to protect it against dynamic loads caused by earthquakes.

The Fly's Eye Project is a high resolution, high coverage time-domain survey in multiple optical passbands: our goal is to cover the entire visible sky above the 30° horizontal altitude with a cadence of ~ 3 min. Imaging is going to be performed by 19 wide-field cameras. Using a hexapod mount allows us to create an instrument that does not require manual polar alignment and, in addition, the same mechanics can be used independently from the geographical location of the device. We briefly introduce the design concepts of the instrument and summarize our early results, focusing on the sidereal tracking.

Two-motor application has become a very attractive issue in the field where high performance is permitted to achieve of position, speed, acceleration. In the elevation axis of telescope control system, a two-motor direct drive is proposed in this paper to enhance the high performance of tracking control system. Although there are several dominant strengths such as low size of motors and low torsional structural dynamics, the synchronization control of two motors is still an essential part. Thereby, in this paper ,a three-closed-loop control technique based on master-slave current control is used to synchronize two motors; the three loops are current control loop ,velocity control loop and position control loop. Firstly, the direct drive function of two motors is modeled. Compared with the single motor direct control system, the resonance frequency of two-motor control systems stays the same, while the anti-resonance frequency of two-control system rises to 1.414 times higher than that of the single motor drive control system. Because of the hard coupling for direct drive, the speed of two motors of the system remains the same, while the current of the two-motor drive control is different. Therefore, the current master-slave control technique is proposed to effecitively synchronize the torque, in which the current loop of the master motors is tracked by the other slave motor, thereby the velocity of the master motor feedbacking into the input of current loop. Several experiments have been done to prove the high performance of two-motor direct drive control for elevation axis of telescope.

Hydrostatic bearings provide high load capacity and stiffness with a minimum of friction, and power consumption. Hydrostatic bearings are reliable and have no metal-to-metal contact. The bearing consists of a pair of metal plates in close proximity; oil is pumped into the gap between these plates to float the structure on an oil film. This oil film provides very high axial stiffness with negligible sliding friction. The bearings must resist tilt and provide sufficient load capacity to maintain the oil film thickness. A simple technique has been developed to model the pressure distribution and flow in the bearing film for and uniform film thickness. This provides information moment restoring forces, film stiffness, viscos friction, and power requirements for a variety of temperatures, supported loads and oil viscosities.

Korea Astronomy and Space Science Institute have been developing the Korea Microlensing Telescope Network aka KMTNet consists of three identical 1.6-m wide-field optical telescopes to discover Earth mass extrasolar planets using a microlensing method. We present the test results and verify the observational performance of the first system installed at CTIO. The test results will include: telescope pointing accuracy and repeatability, tracking accuracy, delivered image quality, profile variation of the point spread functions throughout a wide-field focal plane, signal to noise ratio as a function of magnitude, programmed observation mode, etc.

A prototype of wide field telescope of 2° field of view is a Cassegrain type telescope with a 0.5 m primary mirror and a 0.2 m secondary mirror with multiple correction lenses. Design optimization of telescope has been conducted with various opto-mechanical analyses under gravity, temperature and dynamic loads by using finite element analyses. Optical performance evaluation and image motion are also calculated based on line of sight sensitivity equations integrated in finite element models. Manufacturing of optical elements, telescope structure and alignment, install and test observation of a wide field telescope will be discussed.

The Design Verification Antenna (DVA-1) telescope is a technology development project intended to inform the design, construction and testing of a novel antenna design appropriate for the large-scale production and high performance/cost ratio needed for the Square Kilometre Array (SKA). The DVA-1 consists of a rim-supported composite 15-m off-axis paraboloid primary reflector and 4-m diameter rim-supported composite secondary reflector. Providing the support and positioning of the primary reflector is a very stiff, steel tubular structure that connects to the pier mount which provides pointing control. This study details the design, analysis, construction and performance evaluation of the carbon-fibre composite primary dish, the steel tubular primary dish support structure (PDSS) and the structural interface between these structures called the dish rim connectors (DRC). Finally, the initial mechanical measurement and performance are quantified and compared to those predicted.

The 150-spectrograph VIRUS instrument consists of 75 unit pairs and is housed within two mirror-image environmental enclosures on either side of the HET structure. A support structure was designed and installed to suspend the enclosures and couple them to the telescope system. Modal and dynamic analysis techniques were employed to optimize the support system and eliminate the potential for overturn in the event of a sudden stop during an azimuth rotation. Additional design considerations included working around the existing HET structure and breaking it up into bolt-together sections to facilitate assembly within the HET enclosure.

The Panoptic Astronomical Networked OPtical observatory for Transiting Exoplanets Survey (PANOPTES) project is aimed at identifying transiting exoplanets using a wide network of low-cost imaging units. Each unit consists of two commercial digital single lens reflex (DSLR) cameras equipped with 85mm F1.4 lenses, mounted on a small equatorial mount. We describe the hardware and software for the PANOPTES project, focusing on key challenging aspects of the project. PANOPTES is both an outreach project and a scientifically compelling survey for transiting exoplanets.

The Dome Shutter Drive System on the CFHT Observatory experienced two, separate, catastrophic failures recently; leading to a full-blown, company-wide investigation to understand and determine the root cause of both failures . My paper will attempt to describe in detail the problems encountered, investigations performed, analysis developed, and solutions integrated.
The first event on the evening of December 15, 2011 sheared the Drive Pinion Star Wheel on Drive #3; causing the shutter to stall approximately 2-panel widths from the fully closed position. The second event on the morning of April 14, 2012 sheared the Drive Pinion Star Wheel on Drive #4 leaving the shutter completely open; forcing the longest Shutdown effort (67-nights) ever recorded at CFHT.
The Technical Staff was divided into essentially two working groups; the Mechanical Systems Group and the Controls Working Group. The Mechanical Group focused their attention on the physical inspection of All Shutter Drive Hardware; Drives, Brakes, Gear Reducers, Rack Assembly, Guide Rollers, etc. while the Controls Group researched the Electrical and Software interface; PLC Code, Motor Controllers, Cord Reels, Brake Relays, Overloads, Ammeters, etc.
Multiple resources were utilized to detect and reveal clues to help determine the cause of failure. Former colleagues were consulted, video footage investigated, ammeter plots dissected, Solid Models developed, Forensic Analysis of failed shafts performed, Controller mock-up established; all in an attempt to gather data, understand the System, and develop a clear path solution to resurrect the Shutter and return it to Normal Operation.
Extensive research and testing efforts eventually returned the Shutter to everyday operations. Ongoing efforts are being conducted to rebuild and replace vital components. Future upgrades were identified and will be evaluated for implementation.

The Planets Telescope structure is a unique solution to an off-axis telescope that combines carbon tubes with an aluminum hub and mirror support structure. This design started as a space frame configuration that contained only tension/compression members and nodes connecting members that were purposely designed not to carry a moment. The initial configuration was designed based on a coarse representation of loads and boundary conditions. As realism in the boundary conditions and a better definition of loads evolved, the tension/compression solution performance was surpassed by a more traditional truss design with carbon tubes and metallic, stiff nodes. The current design has been analyzed for closed loop line-of-sight jitter in the presence of wind loading and uniform temperature changes using a finite element model combined with actual dynamic wind pressure measurements and optical sensitivities derived from the optical prescription.

The Giant Magellan Telescope (GMT) is an optical-infrared 25 Meter ELT to be located in Chile. The Gregorian Instrument Rotator (GIR) is a large assembly with a mass of 110,000 kg. It will be supported by a unique bearing system which will have the advantages of adjustability, low friction, low noise (jitter), and low cost. A test was implemented to confirm bearing life and to measure friction. The bearing system design and test details and results are described.

The University of California Observatories will design and construct
a deployable tertiary mirror (named K1DM3) for the Keck 1 telescope,
which will complement technical and scientific advances in the area of
time-domain astronomy. The K1DM3 device will enable astronomers to
swap between any of the foci on Keck 1 in under 2 minutes, both to
monitor varying sources (e.g. stars orbiting the Galactic center) and
rapidly fading sources (e.g. supernovae, flares, gamma-ray bursts).
In this paper, we highlight the scientific motivations for K1DM3 and
report on the design development.

The KPNO Nicholas U. Mayall 4-meter telescope is to be the host facility for the Dark Energy Spectroscopic Instrument (DESI). DESI will record broadband spectra simultaneously for 5000 objects distributed over a 3-degree diameter field of view; it will record the spectra of approximately 20 million galaxies and quasi-stellar objects during a five-year survey. This survey will improve the combined precision of measurement on the dark energy equation of state today (w0) and its evolution with redshift (wa) by approximately a factor of ten. Installation of DESI on the telescope is a complex procedure, involving a complete replacement of the telescope top end, routing of massive fiber cables, and installation of banks of spectrographs in an environmentally-controlled lab area within the dome. Furthermore, assembly of the instrument and major subsystems must be carried out on-site given their size and complexity. A detailed installation plan is being developed early in the project in order to ensure that DESI and its sub-systems are designed so they can be safely and efficiently installed, and to ensure that all telescope and facility modifications to enable installation are identified and completed in time.

Telescopes are servo mechanisms composed by structures rotating around two main axes (if we exclude the derotation). Science has progressed, and it needs telescopes to reach more and more extreme pointing precisions. This has made designers to start using technologies typically employed in the machining tools. Therefore, from telescopes (and radiotelescopes) using supports constituted by wheel-on-track systems there has been a shift towards the use of high precision roller bearings and hydrostatic bearing systems.

The closed-loop correction must be carry out before observation of Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) to eliminate the low-frequency errors. A natural guide star S-H sensor in the focal plane of LAMOST is used to conduct wavefront sensing. The designed limiting magnitude of the S-H sensor is 10th magnitude, and the beacon must be located in the center of field of view, or slightly deviated from the center. The survey time of LAMOST is 2 hours before and after transit, wherefore the active optical correction should be completed within half of an hour, so it is necessary to make the wavefront sensing time as short as possible. Since the magnitude of guide star and atmospheric seeing have important effect on the efficiency of wavefront sensing, 9th magnitude or brighter stars are adopted in operation. For 9th magnitude stars, sky coverage will be about 100%, but at most of time, the beacons are not located in the center of field of view, so we propose to design a laser guide system based on Rayleigh scattering to provide a beacon whose brightness is equivalent to a 7th or 8th magnitude star and to launch the beacon in the center of field of view at any observational sky. In this paper, we describe the optical design of the implementation involved a laser system with 532nm in wavelength, beam diagnostics, a launch telescope with 350mm in diameter, and receiving wavefront sensor.
The closed-loop correction must be carry out before observation of LAMOST. The survey time of LAMOST is 2 hours before and after transit, wherefore the active optical correction should be completed within half of an hour. Since the brightness of beacon and atmospheric seeing importantly affect the efficiency of sensing, so we propose a laser guide system to provide a beacon whose brightness is equivalent to a 7th or 8th magnitude star and to launch the beacon in the center of field of view at any observational sky. In this paper, we describe the optical design of the implementation.

To substantially upgrade the Blanco telescope a new Dark Energy Camera (DECam) was developed. The Blanco telescope was design and built in 1975 before the benefits of modern heavy, instruments were foreseen. Consequently, the mass of DECam is greater than the original instrument payload. The telescope mount was rebalanced about the elevation assembly by redesigning the Cassegrain cage to accommodate a significant increase in balancing mass. Finite element analysis was used to both determine the structural integrity of the new telescope configuration and predict the effects of this added mass on the relative displacement between the primary and secondary mirrors.

The real-time maintenance sensor for the radio active reflector is one of the key technologies for the active reflector upgradation plan of 13.7m millimeter radio telescope from Purple Mountain Observatory, China. A new type of maintenance integration sensor based on PSD and laser module based on normal angle and distance detection is proposed in this paper. After the brief introduction of the maintenance theory of the radio telescope segmented primary reflector, the method is simulated and tested on the real backup panel from the telescope in the active reflector lab in Nanjing Institute of Astronomical Optics and Technology, China. The method is proved to be a high accurate, engineering feasible for that real-time maintenance of the whole primary. Finally some conclusions are reached.

In order to realize the active surface upgrade on the Delingha 13.7-m millimeter telescope, an experiment based on the two spare panels has been carried out recently. During the experiment, we solved the critical development difficulties involved in an active surface: practical development and implementation of the precision linear actuator, control of the actuators and the experimental active surface. And we also explored surface maintenance technology. The successful design, test and experiment confirmed that the developed technologies associated with active surface have got ready for the practical implementation of the active surface update of the Delingha telescope.

In an inauspicious start to the ultimately very successful installation of the Dark Energy Camera on the V. M. Blanco 4-m telescope at CTIO, the light-weighted Cer-Vit 1.3-m-diameter secondary mirror suffered an accident in which it fell onto its apex. This punched out a central plug of glass and destroyed the focus and tip/tilt mechanism. However, the mirror proved fully recoverable, without degraded performance. This paper describes the efforts through which the mirror was repaired and the tip/tilt mechanism rebuilt and upgraded. The telescope re-entered full service as a Ritchey-Chretien platform in October of 2013.

We present the Mercator telescope, a 1.2-m telescope, installed at the Roque de Los Muchachos Observatory on La Palma. Mercator became operational in 2001 and has since seen several upgrades. We present an update about the telescope status and its performance. We also give an overview of the instrument suite, the scheduling software and the telescope exploitation scheme, and how this serves the main research themes of Mercator. Finally, we discuss two important upcoming upgrades: a long-awaited automatic mirror cover and an entirely new PLC-based telescope control system that relies on OPC UA communication technology.

The concept of "Virtual Image Slicer" was developed and implemented at the Very Large Telescope (VLT). The Virtual Image Slicer consists in elongating the stars in a given direction by the use of the Active Optics of the telescope. Alignment of the major axis of the elongated star along the entrance slit of the spectrograph allows to increase the total signal collected in a single (polarimetric) spectrum by a factor of up to 100 or more relative to a perfectly shaped image for bright sources.

The Dark Energy Spectroscopic Instrument (DESI) will measure the effect of dark energy on the expansion of the universe. It will obtain optical spectra for tens of millions of galaxies and quasars, constructing a 3-dimensional map spanning the nearby universe to 10 billion light years. The guide, focus and alignment system (GFA) cameras are the eyes of the DESI system. It provides field acquisition, guiding and focus and alignment measurements to help provide maximal optical throughput for the science targets. We describe the baseline design for the GFA system and describe its operation during a typical science exposure.

A major upgrade of the HET is in process that increases the pupil size to 10 meters and the field of view to 22’ by replacing the four-mirror corrector and prime focus instrument package to track motions of astronomical targets. To support the payload a new Tracker was designed, built and tested at the University of Texas Center for Electromechanics, in Austin, Texas. It was then disassembled and installed on the HET. Testing in the laboratory, as well as subsequent commissioning tests, confirm that the Tracker will position the payload to acquire and track within the specified requirement.

The DAG (Turkish for Eastern Anatolia Observatory) 4-m telescope project has been launched in March 2014, being fully funded by the Government of Turkey. This new observatory will be located on a 3000 m ridge near the town of Erzurum. First light is scheduled for late 2017.
The DAG team’s baseline design of the telescope consists of a Ritchey-Chretien type with alt-az mount, a focal length of 56 m and a FoV up to 30 arcmin. Multiple instruments will be located at the Nasmyth foci. The optical specifications of the telescope are set by DAG team for diffraction limited performance with active and adaptive optics.

A new type telescope which can measures three dimension positions of space debris has been designed. A CCD camera is installed on the principal focus to measure direction of space debris with reference to stars, meanwhile, a single-photon avalanche diode (SPAD) is installed on the cassegrain focus to measure distance between the space debris and the telescope when a powerful laser transmits laser to the space debris. The draft of optical and mechanical design will be presented.

We describe our six year experience and the specific technical and environmental challenges we had to overcome in running a telescope in the Arctic, during the polar winter. We present the solutions implemented for the remote control and maintenance of our facility in the presence of extreme and unique conditions for instrumentation control at a remote site. We also summarize the observational challenges for making precise and reliable photometric observations.

Gaia is a European Space Agency cornerstone mission launched 19 December 2013 from French Guyana. Gaia will map the sky down to the 20th magnitude for point sources. Astrometry and photometry is done for all detected objects and spectroscopy down to magnitude limit 16. At the moment of writing this abstract Gaia is being commissioned. All subsystems have been successfully operated. Gaia is in its operational orbit around L2 point. The attitude control with use of the stars from the science instrument has been successfully executed. The alignment of optical elements is on-going with an iterative process involving focusing and spin speed adjustments as well. The Focal Plane Assembly is fully functional with all 106 CCDs operational and the Phased Array Antenna can transmit all science data down. The commissioning phase is anticipated to last till May 2014. The nominal operations are scheduled for 5 years. The scientific yield is expected to contain a billion stars with positions, distances and proper motions based on astrometry. With photometry the stellar properties of this sample can be deduced. Finally from the spectroscopy Gaia allows extraction of some 150 million radial velocities for the brightest stars. This information will allow addressing the main scientific goals of Gaia concerning the structure, history and evolution of our Milky Way Galaxy. In addition to Galactic structure, Gaia will allow addressing various other science areas. For stellar astrophysics Gaia will provide the long awaited distances and census of multiple star systems. Gaia is expected to discover few thousand exo-planets. The main belt asteroid orbits will be improved significantly. Eventually even fundamental physics can be done with tests on general relativity. The presentation will summarize the status of the spacecraft and provide updated scientific performance estimates based on the in-orbit data from the commissioning phase.

The Atacama Large Millimeter/submillimeter Array is transitioning from construction to operations. This connected element array currently operates from wavelengths of 3-mm to 350-microns with up to 66 array elements, 54 of 12-m diameter and 12 of 7-m diameter. While the antennas and most of the hardware for the receivers are on site, array capabilities are still expanding rapidly. In parallel with construction activities, early science observations have been going on since October 2011. At the time of the meeting, ALMA will be starting the third cycle of observing with many exciting, fundamental results already obtained. We will present the current status of the project and give an overview of the trailblazing science results obtained so far. The potential of the fully operational ALMA will be outlined as well as some of the development projects that are considered. In summary, this talk will address the past, present and future of ALMA, describe the transformational science that is and will be produced with ALMA.

Coffee Break 10:00 AM - 10:30 AM

Session 12:
Telescopes and Arrays for Surveys, Time-domain and Transient Observations I

The Pan-STARRS telescopes are a distributed aperture approach to rapid, multi-color wide-field surveys. The first of these telescopes, a prototype designated PS1, has been in operation now for over three years and has already obtained complete sky coverage of the full 3-pisteradians visible from Haleakala in 5 broad passband filters at multiple epochs. On average the PS1 survey has obtained approximately 12 epochs though each filter. The second telescope, designated PS2, has been in its commissioning phase since August 2013 and will begin science operations in the second half of 2014.
Several design and fabrication changes in both the telescope and the camera have been implemented in PS2. This talk will describe the science results that have been coming out of the PS1 survey, the design changes implemented on PS2, and the current performance of the PS2 telescope and camera. We will also describe the future missions for the PS1 and PS2 telescopes as of the current year.

Current time-domain wide-field sky surveys generally operate with few-degree-sized fields and take many individual images to cover large sky areas each night. We present the design and project status of the Evryscope ("wide-seer"), which takes a different approach: it instead places a pixel on every part of the sky, making it a 7cm telescope pointed at every part of the visible sky simultaneously and continuously. The Evryscope is a gigapixel-scale imager with a 9060 sq. deg. field of view and has an etendue three times larger than the Pan-STARRS sky survey. The system will search for transiting exoplanets around bright stars, M-dwarfs and white dwarfs, as well as detecting microlensing events, nearby supernovae, and gamma-ray burst afterglows. We will present the current project status, including an update on the Evryscope prototype telescopes we have been operating for the last three years in the Canadian High Arctic, and the detailed design of the under-construction full system.

SONG (Stellar Oscillation Network Group) is an international project to form a global observing network of eight 1-meter class telescopes. China joined this project and funded one node telescope for this network. By the end of 2013, the Chinese SONG telescope has been installed on the Delinha observing site of Purple Mountain Observatory in Qinghai province. This paper will give an introduction of this telescope, including its optical system, structure and control system. Besides, the preliminary observing performance of the telescope on site will be given in the second part of this paper. Meanwhile, some experience and lessons, such as alignment and adjustment, will be shared in this paper.

Liverpool Telescope 2 will be a fully robotic 4-metre class telescope co-located on the Canary Island of La Palma with the existing 2-metre Liverpool Telescope. LT2 will be dedicated to time domain astronomy, with a focus on extremely rapid follow-up of explosive transients discovered with the next generation of ground- and space-based survey facilities. In this talk I will discuss the role for Liverpool Telescope 2 in the 2020+ astronomical landscape, the key science topics we hope to address, and the results of our preliminary optical and mechanical design studies.

The Large Synoptic Survey Telescope (LSST) Project is a public-private partnership that has recently completed its Final Design Review, an important step toward potential construction funding. The science objectives remain consistent with the New Worlds New Horizons Decadal endorsement of the LSST. The engineering requirements and designs have matured around a 3-mirror wide field optical system with an 8.4 meter primary mirror and a 64 cm 3.2 gigapixel focal plane camera. The data management system will reduce, transport, alert, and archive the 15 terabytes of data produced nightly. The Project is preparing for a 2014 construction authorization.

The Transneptunian Automated Occultation Survey (TAOS II) will aim to detect occultations of stars by small (~1 km diameter) objects in the Kuiper Belt and beyond. Such events are very rare (0.001 events per star per year) and short in duration (~200 ms), so many stars must be monitored at a high readout cadence. TAOS II will operate three 1.3 meter telescopes at the Observatorio Astronómico Nacional at San Pedro Mártir in Baja California, México. With
a 2.3 square degree field of view and a high speed camera comprising CMOS imagers, the survey will monitor 10,000 stars simultaneously with all three telescopes at a readout cadence of 20 Hz.

MASCARA, the Multi-site All-Sky CAmeRA, consists of several fully-automated stations distributed across the globe. Its goal is to find exoplanets transiting the brightest stars, in the V = 4 to 8 magnitude range. Each station contains five wide-angle cameras monitoring the near-entire sky at each location.
In order to fulfil its science goal, MASCARA has to reach a minimum signal to noise ratio of 100 at the faint end in less than one hour. We describe here the background behind MASCARA, the concept of the first station, and the results of the first observing run.

The Maunakea Spectroscopic Explorer (MSE; formerly ngCFHT) project will replace the existing 3.6 m Canada-France-Hawaii Telescope with a 10 m wide field spectroscopic facility. Capable of recording tens of thousands of spectra on faint targets each night, and sustain that pace for years, MSE will be an ideal complement to emerging space- and ground-based imaging surveys. The combination of aperture and dedicated access to support large surveys makes MSE distinct from any other facility under development or being planned. We provide an overview of the MSE technical design, status of the project’s partnership, and the science goals that will propel MSE for decades.

Wavefront sensing and the Active Optics System (AOS) of the Dark Energy Camera (DECam) at the CTIO 4-meter Blanco telescope are described. DECam utilizes four pairs of intra/extra-focal CCDs located on the edge of the focal plane for wavefront sensing. Out-of-focus stars are selected, individually fit to a pupil plane Zernike expansion and then analyzed in the time between exposures. The AOS uses this information to control the prime-focus camera's five degrees of freedom. The AOS is now in routine use, operating with unsupervised control of the focus and camera alignment, both for the Dark Energy Survey and community observing. The design, commissioning and operation of the AOS along with results from the wavefront measurements are described. In particular, wavefront measurements of the complete optical system, including primary mirror aberrations, are shown. Lastly, preliminary results using these wavefront measurements to model the DECam point spread function are presented.

LAMOST is a special reflecting Schmidt telescope with both large aperture (about 4m) and wide field of view (5 degrees). Its focal surface accommodate 4000 optical fibers which connect to 16 spectrographs with 32 CCD cameras. LAMOST is the telescope of the highest spectrum acquiring rate.
From October 2011 to June 2013, LAMOST has obtained more than 2 million spectra of celestial objects. There are 1.7 million spectra of stars, in which the stellar parameters of more than 1 million stars was obtained. LAMOST will make important contribution to the research of the structure and evolution of the Galaxy.

The LSST is an 8.4 meter, 3.5 degree, wide-field survey telescope. The survey mission requires a short slew, settling time of 5 seconds for a 3.5 degree slew. Since it does not include a fast steering mirror, the telescope has stringent vibration limitations during observation. Meeting these requirements will be facilitated by a compact Telescope Mount Assembly (TMA) riding on a robust pier, which produces high natural frequencies, an advanced telescope control system (TCS) to minimize vibration excitation and by reaction mass dampers. The design is an altitude over azimuth welded and bolted assembly fabricated from mild steel.

The Maunakea Spectroscopic Explorer (MSE; previously, the Next Generation CFHT) will fill what is arguably the 'missing link' in the international suite of optical-infra-red facilities in the 2020s, and a key capability for multi-wavelength science, namely: fully dedicated, 10m-class, wide-field spectroscopy of thousands of objects per hour at spectral resolutions ranging from R=2000 to 20000. This facility will be provided by recycling the existing CFHT and expanding the partnership, and a Project Office has been established to lead the continued scientific, technical and partnership development and complete a Construction Proposal for the facility. Here, I will review the current status of the science development, in particular discussing the mechanisms by which the principal science drivers are flown into the technical design, and I will discuss how the facility will be optimised to satisfy demanding scientific specifications.

The Large Synoptic Survey Telescope (LSST) has recently completed its Final Design Review and the Project is preparing for a 2014 construction authorization. The telescope system design supports the LSST mission to conduct a wide, fast, deep survey via a 3-mirror wide field of view optical design. Several early procurements of major telescope subsystems have been completed and awarded. These early contracts provide for the final design of interfaces based upon vendor specific approaches and will enable swift transition into construction. The status of these subsystems and future plans during construction are presented.

We compare different strategies to minimize the effects of telescope vibrations to the differential piston (OPD) for LINC/NIRVANA at the LBT using an accelerometer feedforward compensation approach. Model based estimation and broadband filtering techniques can be used to solve the estimation task, each having its own advantages and disadvantages, which will be discussed. We explain our laboratory setup aimed at imitating the vibration behaviour at the LBT in general, and we demonstrate the controllers ability to suppress vibrations in the desired frequency range. We show experimental results, indicating the ability to reduce differential piston by a factor of 6 (RMS), which is significantly better than any currently commissioned system.

The Multi Unit Spectroscopic Explorer (MUSE) is a second-generation VLT panoramic integral-field spectrograph. The instrument has been designed to take advantage of the VLT ground layer adaptive optics ESO facility using four laser guide stars. MUSE couples the discovery potential of a large imaging device to the measuring capabilities of a high-quality spectrograph, while taking advantage of the increased spatial resolution provided by adaptive optics. The MUSE hardware is composed of 24 identical modules, each one consisting of an advanced slicer, a spectrograph and a (4k)^2 detector. A series of fore-optics and splitting and relay optics is in charge of derotating and partitioning the square field of view into 24 sub-fields. With its almost 7 tons of opto-mechanics, MUSE is one of the biggest integral field unit ever built.
After a successful preliminary acceptance in Europe in fall 2013, MUSE has been dismounted, shipped to Chile and re-integrated in the Paranal new integration hall and finally installed on the Nasmyth platform of UT4 late January this year. During the 2 commissioning runs, hundreds of millions of spectra have been obtained in order to validate the instrument and measured its achieved performance. To demonstrate its power, a number of show-case and spectacular observations have also been obtained. Preliminary results demonstrate that MUSE is likely to become a new reference in the field of integral field spectroscopy thanks to its large field of view, very high throughput, excellent image quality, good spectral resolution, wide simultaneous spectral range and state-of-the art control and data reduction software.
I will review this success story, from the call of idea to the deployment on the VLT, including the latest performances and showcase observations.

Canadian astronomers have participated in space astronomy since the first OAO missions in the 1960s and 1970s. Individual Canadian scientists have been members of HST instrument teams, and advisory groups for IUE and HEAO missions, as well as competing successfully for observing time on NASA, ESA, and Japanese astronomy satellites. With the formation of the Canadian Space Agency, Canada became partner in the FUSE mission, the ISRO Astrosat, and the JWST, providing hardware and science team membership. The Canadian Astronomy Data centre was one of the three original world-wide archive distribution centres for HST, and now is involved in many space and ground-based data services. The MOST observatory is an all-Canadian microsat that has operated for nearly a decade. Canada is currently involved in partnership in a number of imminent space facilities, as well as participating in teams defining future missions. I will describe this history, and review the technical and scientific capability that exist in Canada now. I will outline prospects for the future, including a concept for a high resolution orbiting telescope that will fill the gap in high resolution UV astronomy when HST operations cease.

The Giant Magellan Telescope (GMT) is a 25 m, optical/infrared telescope that is being built by an international consortium of universities and research institutions as one of the next generation of Extremely Large Telescopes. The project has recently completed a series of sub-system and system-level preliminary design reviews and is currently preparing to move into the construction phase. This paper summarizes the technical development of the GMT sub-systems and the current status of the GMT project.

The Thirty Meter Telescope is an optical/infrared telescope that will be located near the summit of Mauna Kea on the big island of Hawai'i. This paper will provide an overview of progress in formation of the international partnership, approval of the environmental and regulatory permits for construction on Mauna Kea, design of the facility, telescope, adaptive optics systems and instruments, and fabrication and testing of prototype subsystems, including full-scale full-asphericity primary mirror segments.

The 39-m E-ELT is an approved project of the European Souther Observatory. Construction
contracts have been initiated for the large (2.5-m) adaptive deformable mirror and for the
site preparation (leveling of the top and construction road) at Cerro Armazones in Northern
Chile. The first light instrumentation (an integral field spectrograph and a diffraction limited
multi-conjugate adaptive optics fed camera/spectrograph) have been approved and the three
next instruments are in the definition phase. An overall presentation of the telescope, its capabilities
and its instrumentation complement shall be made. The presentation shall focus on the recent
developments in the area of design and prototyping and the plans for the construction period.

The preliminary design of the 25 m Giant Magellan Telescope (GMT) has been completed. This paper describes the design of the optics, structure and mechanisms, together with the rationales that lead to the current design. Analyzes that were conducted to verify structure and optical performance are summarized. Science instruments will be mounted within the telescope structure. A common instrument de-rotator is provided to compensate for field rotation caused by the alt-az tracking of the telescope. The various instrument stations and provisions for mounting instruments are described. Post-PDR development plans for the telescope are presented.

An international consortium of scientists, engineers, and private interests formed in 2012 to develop key technologies required to build a large telescope with the capability of detecting life signatures, and potentially even Earth-like civilizations, on hundreds of nearby exoplanets. This “Colossus Telescope” departs from currently planned large optical telescopes in order to achieve a high level of coronagraphic performance, angular resolution, and flux sensitivity. As a nearly filled-aperture, highly redundant-baseline optical and IR imaging instrument, it has several advantages for studying exoplanets and circumstellar environments. The Colossus will use new concepts for its thin-glass mirror optics, mirror optical phasing, and telescope enclosure structure.

The GMT primary mirror support draws on the heritage of supports developed for the 3.5 m, 6.5 m, and 8.4 m mirrors from the Steward Observatory Mirror Lab. Each generation of mirrors has seen improvements in the support design. The GMT has new challenges for the supports due to project scale and mirror positioning. Improvements have been made to the support components for additional performance and increased reliability.

The E-ELT is an active and adaptive 39-m telescope, with an anastigmat optical solution (5 mirrors including two flats), currently being developed by the European Southern Observa-
tory (ESO).
The convex 4-metre-class secondary mirror (M2) is a thin Zerodur meniscus passively supported by an 18 point axial whiffle-tree. Laterally the mirror is supported on 12 points along the periphery by pneumatic jacks. Due to its high optical sensitivity, the M2 unit needs to allow repositioning the mirror during observation. Considering its exposed position 30m above the primary, the M2 unit has to provide good wind rejection. The M2 concept is described and major performance characteristics presented.

The Thirty Meter Telescope (TMT) is a next-generation optical/infrared telescope to be constructed on Mauna Kea, Hawaii toward the end of this decade, as an international project. Its 30 m primary mirror consists of 492 off-axis aspheric segmented mirrors. High volume production of hundreds of segments has started in 2013 based on the contract between National Astronomical Observatory of Japan and Canon. This paper describes the achievements of the production trials. The stressed mirror fabrication technique which is established by Keck Telescope engineers is arranged and adopted. To measure the segment surface figure, a novel stitching algorithm is evaluated by experiment. The procedure of production will be improved in a near future.

During the last 2 years ESO has operated a M1 prototype test facility consisting of a representative section of the E-ELT primary mirror equipped with 4 complete prototype segment subunits including sensors and actuators. The purpose of the test facility is twofold, on the one hand it serves to study component and system aspects like calibration, alignment and handling procedures and suitable control strategies on real hardware long time before the M1 components are commissioned. On the other hand, which turned out to be the main benefit of the test facility, it offered the possibility to evaluate component and subsystem performances and interface issues in a system context in such detail, that many issues could be identified early enough in the project to feed them back into the subsystem and component specifications. This considerably reduces cost and risk of the production units and allows to refocus the project team on important issues for the follow-up of the production contracts.

Detecting an exoplanetary life signal requires highly accurate adaptive optics, a coronagraph system, and a specially designed and aligned giant telescope. We present here new strategies for building such a telescope with large circular segments using adaptive optics correction independently for each of these segments prior to cophasing the segments. The foreseen cophasing technique uses focal plane images that allow piston measurements and correction between all the segments. In this context we propose to derive the segment phase error using the inverse approach knowing the segment positions and the single aperture Airy function. We performed detailled simulations of this cophasing scheme including adaptive optics correction. We demonstrate that a natural star can be used successfully by a multiwavelength focal-plane image sensor to cophase in real time a telescope composed of sixty 8m circular segments and to reach very high contrast compatible with imaging of extrasolar planets.

The Giant Magellan Telescope (GMT) is one of Extremely large telescopes, which is 25m in diameter featured with two Gregorian secondary mirrors, an adaptive secondary mirror (ASM) and a fast-steering secondary mirror (FSM). The FSM is 3.2 m in diameter and built as seven 1.1 m diameter circular segments conjugated 1:1 to the seven 8.4m segments of the primary. The guiding philosophy in the design of the FSM segment mirror is to minimize development and fabrication risks ensuring a set of secondary mirrors are available on schedule for telescope commissioning and early operations in a seeing limited mode. Each FSM segment contains a tip-tilt capability for fine co-alignment of the telescope subapertures and fast guiding to attenuate telescope wind shake and mount control jitter, thus optimizing the seeing limited performance of the telescope. The final design of the FSM mirror and support system configuration was optimized using finite element analyses and optical performance analyses.

The primary mirror control system (M1CS) keeps the 492 segments of the Thirty Meter Telescope primary mirror aligned in the presence of disturbances. A review of the M1CS control design is presented and shows that the control system has remained robust to changes in the structural models. Identified risks include control structure interaction due to actuator forces reacting with the mirror cell and due to uncertainties in the structural model, particular at frequencies above 50 Hertz. The paper describes three risk reduction strategies, each of which addresses both of these risks.

The proposed control system for the M5 unit has two main local loops: A damping loop based on a velocity feedback derived from filtering accelerometers installed next to the actuators, and a local position loop based on the signal from position sensors measuring the relative expansion of the actuators. A configurable control loop programmed in a remote I/O FPGA unit has been prototyped in order to test different active damping and position loop strategies. The objective is to prototype E-ELT control system standards and further study active damping strategies. We present the current status of the prototype M5 control system and the latest results on the active damping control strategy.

CCAT will be a 25-meter telescope for submillimeter wavelength astronomy located at an altitude of 5600 meters on Cerro Chajnantor in northern Chile. This paper presents an overview of the preliminary mount control design. A finite element model of the structure has been developed and is used to determine the dynamics relevant for mount control. Innovative control strategies are presented to meet challenging wind rejection and fast scan requirements. A command shaping architecture for the mount control system is presented that includes extra sensors, a feedforward network, and a two-command path structure that includes the de-convolution filter.

Session PSWed:
Posters: Wednesday

Wednesday 25 June 20146:00 PM - 8:00 PM
Location: Room 516
Authors should be prepared to display their poster at morning coffee break. Posters for this conference will be on display on Wednesday. The interactive poster session with authors in attendance will be Wednesday evening from 6:00 to 8:00 pm. Authors should remove their posters at the end of the poster session. Posters left displayed will be considered unwanted and will be discarded.

Hyper Suprime-Cam (HSC) is a next generation wide field optical imaging camera built for 8.2 m Subaru telescope. The field of view is 1.5 degree in diameter and the nearly 50 cm image circle was paved by 116 fully depleted CCDs (2k x 4k 15 micron square pixels). To realize a seeing limit imaging at Mauna Kea, the specification on the overall instrument PSF is set as 0.32 arc-second (FWHM). This is crucial for our primary scientific objectives: weak gravitational weak lensing survey to probe dark matter distribution. We started building the camera in 2006, had a first light in 2012 and now in the final phase of the commissioning. The delivered image quality is mostly seeing limit as designed and we once observed the seeing size of 0.43 arc-second (median value over the field of view) in Y-band with 300 seconds exposure. Our 300 nights observing proposal has been already accepted. The program starts in March 2014 and continues over 5 years.

The Transiting Exoplanet Survey Satellite (TESS) will discover thousands of exoplanets in orbit around the brightest stars in the sky. In a two-year survey of the solar neighborhood, TESS will monitor more than 200,000 stars for temporary drops in brightness caused by planetary transits. This first-ever spaceborne all-sky transit survey will identify planets ranging from Earth-sized to gas giants, around a wide range of stellar types and orbital distances.
TESS stars will typically be 30-100 times brighter than those surveyed by the Kepler satellite; thus, TESS planets will be far easier to characterize with follow-up observations. For the first time it will be possible to study the masses, sizes, densities, orbits, and atmospheres of a large cohort of small planets, including a sample of rocky worlds in the habitable zones of their host stars. Full frame images with a cadence of 30 minutes or less will provide precise photometric information for several million stars during observation sessions of several weeks. The brighter TESS stars will potentially yield valuable asteroseismic information as a result of monitoring at a rapid cadence of 1 minute or less. An extended survey by TESS of the Ecliptic caps will provide prime exoplanet targets for characterization with the James Webb Space Telescope (JWST), as well as other large ground-based and space-based telescopes of the future.
TESS will serve as the “People’s Telescope,” with data releases every 4 months, inviting immediate community-wide efforts to study the new planets. The TESS legacy will be a catalog of the nearest and brightest main-sequence stars hosting transiting exoplanets, which will endure as the most favorable targets for detailed future investigations.
TESS has been selected by NASA for launch in 2017 as an Astrophysics Explorer mission.

We quantify the accuracy of the Keck telescope segment surface figure measurements made on sky by the Phasing Camera System (PCS). These measurements are used to determine the settings for the segment warping harnesses in order to minimize the segment surface errors. We quantify the measurement errors as reconstructed by 2nd through 4th order Zernike polynomials. In this paper we investigate and quantify the differences in measurement errors using lenslet arrays of two different geometries, on the same night. It is important to understand the limitations of these measurements as they constitute a fundamental limit for the performance of segment warping harnesses.

The primary mirror of the E-ELT consists of a mosaic of 798 hexagonal mirror segments whose relative positions will be measured by 4524 so-called edge sensors.The main properties of these three axes edge sensors are nanometric precision, high linearity low sensitivity to temperature and humidity fluctuations as well as high reliability.
This paper presents the outcome of a development carried out by Micro-Epsilon in the framework of prototype activities launched by the European Southern Observatory several years ago.
The performance of inductive sensors based on Embeded Coil Technology are presented as well as results obtained on representative operational conditions.

Future extremely large telescopes require segmented primary mirrors, each of which should be actively controlled, e.g. in rigid body motions piston and tip-tilt. For this each segment needs to be equipped with three dedicated single-DOF actuators. These piston-tip-tilt actuators should combine ultra-high accuracy with a relatively large stroke, while being exposed to non-stationary structural vibrations and wind loads.
This paper will present recent controller design results by TNO on a prototype for piston-tip-tilt actuators for the E-ELT. This prototype has been tested in the TNO laboratory under circumstances which are in accordance with the most recent specifications for the E-ELT. Using dedicated control engineering and design, this controlled actuator is shown to satisfy the requirements, by achieving 1.4 nm RMS positioning accuracy over the full stroke, in the presence of simulated wind disturbances, while tracking with speeds between 0 and 1.2 μm/s.

The Giant Magellan Telescope active optics system is required to maintain image quality across a 20 arcminute diameter field of view. To do so, it must control the positions of the primary mirror and secondary mirror segments, and the figures of the primary mirror segments. When operating with its adaptive secondary mirror, the figure of the secondary is also controlled. Wavefront and fast-guiding measurements are made using a set of four probes deployed around the field of view. Through a set of simulations we have determined a set of modes that will be used to control field-dependent aberrations without degeneracies.

For highly segmented primary mirrors, like e.g. E-ELT (798 segments), the capability to update regularly the optical phasing solution is essential for robust operations.
The duration of standard phasing procedures is driven by the difficulty of maintaining the registration of the image of the primary on the phasing sensor with tolerances of ~0.03% of the mirror diameter.
The paper describes a re-phasing procedure with a dynamic range of about +/-1.5 microns. This is based on a standard shack-hartmann phasing sensor operated at 2 narrow bands filters with wavelength separation of 30%. Controlled registration offsets are applied during the acquisitions, allowing the registration parameters to be estimated from the phasing data. The procedure has been successfully validated at the GTC.

The Atacama Large Millimeter/submillimeter Array is transitioning from construction to operations. This connected element array currently operates from wavelengths of 3-mm to 350-um with up to 66 array elements, 54 of 12-m diameter and 12 of 7-m diameter. While the antennas and most of the hardware for the receivers are on site, array capabilities are still expanding rapidly. In parallel with construction activities, early science observations have been going on since October 2011. At the time of the meeting, ALMA will be starting the third cycle of observing with many exciting, fundamental results already obtained.
Having now finished construction, we review some of the residual issues we are facing in the transition period. We discuss the current status of the project, array performance, testing, and ongoing development. In short, we will present ALMA: past, present and future.

The Large Millimeter Telescope (LMT) Alfonso Serrano is a bi-national (Mexico & USA) 50-m diameter single-dish millimeter-wavelength facility operating between 70 and 345 GHz, constructed on the summit of Sierra Negra at an altitude of 4600m in the Mexican state of Puebla. Following first-light observations in mid-2011, the LMT project conducted a shared-risk Early Science observing program in 2013 and early 2014, including VLBI observations. The recently commissioned LMT has unique capabilities, compared to existing smaller single-dish (sub-)millimeter-wavelength telescopes, that will enable the study of the formation and evolution of structure at all cosmic epochs. I will briefly describe the current status of the telescope, the instrumentation program and the development plan to improve the performance of the telescope systems, as well as the scientific synergies with the next generations of large telescope facilities.

This work presents a complete study of the optical system for ALMA band 1, which covers the frequency range from 35 to 50 GHz, with the goal of extending the coverage up to 52 GHz. Several options have been explored to comply with the stringent technical specifications, restrictions, and cost constraints. The best solution consists of a corrugated zoned lens, two infrared filters and a spline profiled corrugated horn. The calculated aperture efficiency is better than 77.5%, while the noise contribution is lower than 9 K. The first prototypes of the system have been constructed and initial measurements are shown.

The 2013 saw the completion of the ALMA antennas. This paper presents a summary of the results obtained by the European antennas during the different test campaign and the problems found during the erection with the relative lesson learn.
The results have shown the full correspondence between the design phase and the final product. The antenna Pointing Error has been always excellent. The Fast Motion Capability was an order of magnitude better than the requirements.

The ALMA radio antenna is required to comply with stringent pointing performance of better than 0.6 arcsec rss, which is be verified with an optical pointing telescope (OPT). Our goal is to accurately estimate the pointing errors only of antenna origin. In order to do that, we need to subtract the "components of optical seeing" accurately and add "measured servo errors" to the optical pointing measurement results. With this measurement method, we report that our antennas can meet the specification of the ALMA antenna pointing accuracy by carefully and accurately identifying the optical seeing effects.

ALMA is already producing a growing number of impressive and scientifically compelling results during its first two years of operation. However, ALMA still has some scientific weak points due to the technological limitations. To maintain ALMA as the state-of-the-art facility over the course of its projected life of 30+ years, continuing developments for new capabilities are essential. We identify and report the required technological breakthroughs (e.g. wider field of view, higher sensitivity, higher fidelity imaging, higher angular resolution and wider bandwidth) and future research topics needed in order to realize new scientific requirements based on several science use cases.

During the past year the Square Kilometre Array Project has moved into an aggressive development phase. Since 2008, the global radio astronomy community has been engaged in the development of the SKA in a major effort - the ‘Preparatory’ phase of the project. The Preparatory phase ended in December 2011 and, following a number of major changes, the international SKA project has now progressed to the ‘Pre-Construction’ phase (2012-16). The Member Nations have set up the SKA Organisation, a not-for-profit company founded in the UK to lead activities and the Pre-Construction work has been organised into a series of design work packages to be delivered by consortia from the Member Nations. This paper describes the organisation and scope of the work packages as the project begins the work of preparing for SKA1 construction. It will cover issues of management and value engineering, as well as risk management and systems engineering.

Currently in operation at the DRAO in Penticton BC is a pathfinder version of CHIME (Canadian Hydrogen Intensity Mapping Experiment). The instrument is a cylindrical transit interferometer designed to survey half the sky and measure the cosmological scale neutral hydrogen power spectrum from redshift 0.8-2.5.
The pathfinder consists of two cylinders 37m long by 20m wide oriented north-south. The 128 dual polarization feeds and receivers operate from 400-800MHz. The correlator is an FX design, where the Fourier transform channelization is performed in FPGA's, and the correlation matrix is computed with a set of GPU's.

The paper deals with progresses in development of a novel set of radio frequency sensors to detect the status of the astrophysical infrastructures and capable of possible introduction into the SKA project.
A prototype of a feed array based network has been used as a state of art reflector distortion monitoring sensor that can be considered to improve operational performance of radio astronomy systems. The system is composed by a feed array antenna with n feeders simulator, MiMo NxLxM & DBF Rx in ASIC technology prototype model, electrical I/O prototype interface and mechanical prototype interface.
The work has been oriented to provide: the definition of a simulation model capable of representing the validity of the proposed sensor approach; ASIC mixed signal on line programmable technology state of art development to support requirements; dedicated investigation, critical design and test analysis activity to define validation procedure, focused on the possibility to use a radio frequency feed array sensor system to monitor surface distortions.
A twofold line of work has been adopted. The former is concerned with the definition of a simulation model capable of representing the validity of the proposed sensor approach. The latter is the validation, via a dedicated design and test activity, of the possibility to use a radio frequency sensor system to the monitoring of surface distortions, describing the behaviour of the sensor in terms of noise, phase error, amplitude sensitivity.
A computer program capable of accepting the reflector data inputs (nominal surface point and distortion database to be added), the feed array geometrical characteristics (lattice data) on the equivalent reflector focal plane and other required data is used to evaluate the reflector distortions and the corrections to be introduced either through data reduction software and/or proper actuators operation.
In addition the computer program shall be used for generating the far field pattern of the full antenna, assuming that all the feed element of the feed array are working for the antenna maximum efficiency in three cases corresponding to nominal, a combination of distortion, and the actuated correction.
Performances and features of the ASIC processing chain implemented are discussed together with the simulation model of the full lattice feed array to be used as a distortion sensor of the full size reflector.
Investigation on the full operative feed array network system model emulator (by MiMo & DBF Rx in ASIC prototype tested modelling based) for behaviours prediction report and the basic element of the selected configuration, received values corresponding at the feed positions of the feed array lattice for the cases examined and the correction to be actuated are discussed.

After the successful delivery of the first telescope QUIJOTE (operative since 2012), Idom is currently involved on the turn key supply of a 200GHz telescope. This work will be completed in a challenging period of 11 months (operative in mid-2014), including design, factory assembly & testing, transport and final commissioning on site.
This second unit will improve the opto-mechanical performance and maintainability. The telescope will have an unlimited rotation capacity in azimuth axis and a range of movement between 25º-95º in elevation axis. The pointing and tracking accuracy will be below to 1.76 arcmin and 44 arcsec, respectively.

The Advanced Technology Solar Telescope will be the largest solar
facility ever built. Designed and developed to meet the needs of
critical high resolution and high sensitivity spectral and
polarimetric observations of the sun, this facility will support key
experiements for the study of solar magnetism and its influence on the
solar wind, flares, coronal mass ejections and solar irradiance
variability. Currently, the key subsystems have been designed and
fabrication is well underway. We provide an update on the development
of the facilities both on site at the Haleakala Observatories in Maui
development of components around the world.

Chinese Giant Solar Telescope is the next generation ground-based solar telescope which was formally listed into the National Plans of Major Science and Technology Infrastructures. We have got series progresses of CGST in the recent years, from site testing to detailed designs. CGST is currently designed to be an 8m Ring Interferometric Telescope (RIT). As the comparison in science and technology, the Chinese space solar telescope plans, such as the Deep Space Solar Observatory (DSO) and its progress are simply introduced.

After the successfully finishing the design of the Advanced Technology Solar Telescope (ATST) Enclosure early in 2012, AEC IDOM, in close collaboration with ATST Project Office, has successfully fabricated the enclosure’s main components (structure, mechanisms, controls, and cladding), assembled them in the factory, and performed the factory acceptance tests.
The factory assembly and testing of the enclosure has allowed the team to verify the correct integration and performance of structures, mechanisms, and controls. Furthermore, the assembly and verification procedures to be used for the enclosure re-assembly at the Haleakala High Altitude Observatory site have been tested and refined in order to reduce risk during the enclosure site construction, an overall project critical path activity.

The 1.6 meter, off-axis New Solar Telescope (NST) is the first facility class solar telescope built in the U.S. for a generation and is largest aperture, highest resolution solar telescope in the world until the end of this decade when the 4 m ATST comes online. The NST has regularly provided high resolution data covering the spectral range from 0.4 to 5.0 m to photometrically and polarimetrically probe the solar atmosphere from the deepest photosphere to the base of the corona, and from the quietest to most active Sun. This presentation reports the up-to-date progress on the NST and its next generation instruments.

For better understanding and forecasting of the solar activity and the corresponding impacts human technologies and life on earth, the high resolution observations for Sun are needed. The Chinese large Solar Telescope (CLST) with 1.8 m aperture is being built. The CLST is classic Gregorian configuration telescope with open structure, alt-azimuth mount, retractable dome, and a large mechanical de-rotator. The optical system with all reflective design has the field of view of more than 3 arc-minute. The adaptive optics system will be developed to provide the capability for diffraction limited observations at visible wavelengths. The CLST design and development phase began in 2011 and 2012 respectively. We plan for the CLST’s starting of commission in 2017. A multi-wavelength tomographic imaging system with seven wavelengths range from visible to near-infrared wavelength is considered as the first light scientific instruments.

The Advanced Technology Solar Telescope (ATST) will be the largest solar telescope in the world – with a 4m aperture primary mirror and a 16m diameter co-rotating “coudé” laboratory located within the telescope pier. Both, the telescope mount and the coudé laboratory use for their azimuth axis a new kind of bearing technology, so called R-guides, which minimize later maintenance efforts, avoid energy consumption and the risk of oil spill of conventional hydro-static bearings. The paper describes the integrated modeling approach for the verification of the challenging ATST jitter requirement of 0.075 arcsec rms.

By July 2014, the Automated Planet Finder (APF) at Lick Observatory on Mount Hamilton will have completed its ﬁrst year of operation. This facility combines a modern 2.4m computer-controlled telescope with a ﬂexible development environment that enables eﬃcient use of the Levy Spectrometer for high cadence observations. The Levy provides both sub-meter per second radial velocity precision and high eﬃciency, with a peak total system throughput of 24%. The modern telescope combined with eﬃcient spectrometer routinely yields over 100 observations of 40 stars in a single night, each of which has velocity errors of 0.7 to 1.4 meters per second all with typical seeing of < 1 arc second full-width-half-maximum (FWHM). Since November 2013, the APF has been routinely conducting autonomous observations without human intervention.

Lowell Observatory's Discovery Channel Telescope is a 4.3m telescope
designed and constructed for optical and near infrared astronomical
observation. It is equipped with a cube capable of carrying five
instruments and the wave front sensing and guider systems at the f/6.1
RC focus. We report on the overall operations methods for the
facility, including coordination of day and night activities, and then
cover pointing, and unguided and guided tracking performance of the
mount. We also discuss the implementation and performance of the open
loop model for, and manual wavefront sensing and correction with, the
active optics system. We conclude with a report on the early
integrated image quality and science performance of the facility using
the first science instrument, the Large Monolithic Imager.

The commissioning of the telescope and its first instrument, a Nasmyth port
mounted 0.5 degree CCD imager, started in November 2013. We will report
about the results of astronomical tests of the integrated system including
the archived optical quality accross the field of view, pointing and
tracking quality and operational experiences with the observatory system.
The special design features of this alt-az telescope are its compactness
and the low-ghost wide field optics, and we will
briefly report on the lessons learned especially for these special features.

AMOS S.A. has developed a 2.6 m wide field telescope for the “Observatorio Astrofisico de Javalambre”. The leading edge performance of this telescope has not only required an extensive work of design, analysis and optimization but also a mastered fabrication process and an appropriate AIV plan. The telescope has successfully passed the factory test and is installed at the observatory on the “Pico del Buitre” in Spain. This paper aims to present the philosophy of the test, the results and the current status after installation. AMOS has gained since more than 30 years a huge experience in testing small and large instruments, including optical testing, alignment, mechanical static, dynamic measurements, system identification, etc. It is this combination of various techniques of measurement that produce accurate and reliable results which are a key element of a successful project.

We present an overview of the preliminary design of the TMT Telescope Structure System (STR).
NAOJ was given responsibility for the TMT STR in early 2012 and engaged Mitsubishi Electric Corp. (MELCO) to take over the preliminary design work.
MELCO performed a comprehensive preliminary design study which successfully passed its Preliminary Design Review in November 2013.
Design optimizations to better meet the design requirements were made in the designs of many of the subsystems, including the top end and lower tube of the elevation structure, segment handling system, cable wraps, CO2 snow cleaning arms and seismic isolation and restraint systems.

For decades the optical telescope community has designed their structural systems with hydrostatic bearings for low friction support. At the same time, the radio astronomy community has developed successful wheel and track and rolling element bearing supported designs which accomplish the same task, but in a different way. Now that extremely large telescopes are being developed, it is the author's opinion that as size increases, the hydrostatics have reached the upper limits of practicality. This where wheel and track and conventional bearing designs can be used to accomplish the pointing and tracking needs of extremely large telescopes, while keeping the budget in constraint. This paper will guide you through the needs of such designs to make them effective, economical and reliable.

On 15 October 2006 a large earthquake damaged both telescopes at Keck observatory resulting in weeks of observing downtime. New finite element models were developed to better understand the telescope responses to design earthquakes required by local governing building codes and the USGS seismic data collected at the site on 15 October 2006. The results of two finite element methods, response spectrum analysis and time history analysis, used to determine seismic demand forces and seismic response of each telescope were compared. These models can be used to evaluate alternate seismic restraint design options for both Keck telescopes.

This paper describes the finite element model and analyses of the CCAT Preliminary Design. CCAT will be a 25 m diameter telescope operating in the 0.2 to 2 mm wavelength range. It will be located at an elevation of 5600 m on Cerro Chajnantor in Northern Chile. The main structures of the telescope include a steel Mount and a CFRP primary truss. The finite element model was used to perform modal analyses, seismic response spectrum analyses, frequency response analyses, and deflection and stress analyses of telescope subject to gravitational, thermal, and differential drive torque to support preliminary design work.

The E-ELT as a whole could be classified as an extremely challenging project. More precisely, it should be defined as an array of many different sub-challenges, which comprise technical, logistical and managerial matters. This paper reviews some of these critical challenges, in particular those related to the Dome and the Main Structure, suggesting ways to face them in the most pragmatic way possible.

The Giant Magellan Telescope (GMT), one of several next generation Extremely Large Telescopes (ELTs), is a 25.4 meter diameter altitude over azimuth design set to be built at the summit of Cerro Campanas at the Las Campanas Observatory in Chile.
This paper provides an update and overview of the ongoing efforts for the GMT site, infrastructure, facilities and enclosure design. The paper provides insight of the proposed systems, trade studies and approach resulting in the current design solution.

The Observatorio Astrofísico de Javalambre in Spain is a new astronomical facility particularly conceived for carrying out large sky surveys with two unprecedented telescopes of unusually large fields of view: the JST/T250, a 2.55m telescope of 3deg field of view, and the JAST/T80, an 83cm telescope of 2deg field of view.
This paper describes in detail the engineering development of the overall facilities and infrastructures for the robotic observatory and a global overview of current status and future actions to perform from engineering point of view.

The ESO VLTI using the Unit Telescope was strongly affected by vibrations since the first observations. An important number of investigations on various sub-systems were realized. Vibrations were not only recorded and analyzed using the usual accelerometers but also using on use sub-systems as IRIS and MACAO and using a specific tool developed for vibrations measurements MAMMUT. Moreover, a special test in which 2 UTs instruments were completely shut down was realized to determine the minimum Optical Path Length R.M.S. achievable. Levels of vibrations are regularly recorded to control any environmental change, also a test campaign is held during the installation of any new instrument or system. We will describe some of the measurements method used, the improvement of some system and give a status of the VLTI-UT vibrations evolution.

The NASA/DLR Stratospheric Observatory for Infrared Astronomy (SOFIA) employs a 2.5-meter reflector telescope in a Boeing 747SP. The image stability goal for SOFIA is 0.2 arc-seconds. An active damping control system is being developed for SOFIA to reduce image jitter and degradation due to resonance of the telescope assembly. We describe the vibration control system design and implementation in hardware and software. The system's unique features enabling system testing,
control system design, and online health monitoring will also be presented.

Vibration from equipment mounted on the telescope and in summit support buildings has been a source of optical, and especially adaptive optics, performance degradation at existing observatories. In order to ensure that TMT meets its performance requirements, a vibration budget has been created that specifies allowable force levels from each source of vibration in the observatory. This budget combines: (i) vibration transmission analysis that determines the optical consequences that result from forces applied at different locations and at different frequencies; and (ii) initial estimates for plausible source amplitudes. The transmission of vibration uses the finite element model of the telescope structure, including primary mirror segment models and control loops. Both the image jitter and higher-order deformations due to M1 segment motion are included, along with the spatial- and temporal-correctability by the adaptive optics system.